List of causes of regeneration

The General's Regeneration - Hell Bent - Doctor Who - BBC

A typical Time Lord regenerates — after being shot by the Twelfth Doctor. (TV: Hell Bent)

The causes of regeneration, especially amongst Time Lords, were many and varied.

They ran the gamut from simple desire to change to sentencing for convictions, to life-threatening maladies, to blunt-force trauma. While all of these might have been cause for alarm in humans, Time Lords sometimes expressed much less concern. As the Twelfth Doctor once told Clara, "Death [was] Time Lord for man-flu". (TV: Hell Bent)

The following are the known causes of regeneration of specific Time Lords or other regenerating individuals.

Gallifreyan Time Lords

About the Doctor

N-Space, including alternate or aborted timelines

The Doctor

See also: The Doctor's perspectives on regeneration

The Time Lord known as the Doctor was known to regenerate on several occasions.

Individual	Incarnation	Details	Sources
The Doctor	First Timeless Child	Accidentally fell from a cliff while playing with another child.	TV: The Timeless Children
	Second Timeless Child	Forced to regenerate by the First Tecteun to enable her to decode the "secret" of regeneration.
	Third Timeless Child
	Fourth Timeless Child
	Fifth Timeless Child
	Sixth Timeless Child
	First Doctor	Collapsed due to his "old body wearing a bit thin" after his life force was drained by Mondas, and regenerated with the help of his TARDIS.	TV: The Tenth Planet TV: The Power of the Daleks
	Second Doctor	Forced to regenerate by Time Lord court order as punishment for stealing the TARDIS and breaking the non-interference law. After the sentence was delayed, he was ultimately forced to complete his regeneration by animated scarecrows sent by the Time Lords.	TV: The War Games COMIC: The Night Walkers
	Third Doctor	Radiation poisoning upon prolonged exposure to the Great One's highly unstable web of Metebelis crystals. Drifted through time for ten years dying of the radiation poisoning before he returned to Earth, and had his regeneration triggered by Cho-Je to compensate for the Doctor being unable to trigger it himself.	TV: Planet of the Spiders PROSE: Love and War
		During the War in Heaven, history was altered so that the Third Doctor's regeneration was instead caused by a fatal shot to the chest from Magdelana Bishop. The bullet entered his ribcage at an angle which didn't damage any major organs; he instead died of blood loss.	PROSE: Interference - Book Two
	Fourth Doctor	Fell to the ground from the telescope after battling the Tremas Master at the Pharos Project; merged with the Watcher, a projection of himself who had helped him prepare for his upcoming demise, at the moment of regeneration.	TV: Logopolis
	Fifth Doctor	Contracted spectrox toxaemia on Androzani Minor, triggering regeneration. Regeneration completed after resisting the Master's attempt to stop his regeneration using their shared mental link to Kamelion.	TV: The Caves of Androzani AUDIO: Winter
	Sixth Doctor	According to one account, sustained physical injuries during the First Rani's attack on his TARDIS.	PROSE: Time and the Rani
		According to another account, while suffering from chronon energy starvation after his confrontation with the Lamprey, the Sixth Doctor died from blunt head trauma caused by the Rani's attack.	PROSE: Spiral Scratch
		According to a third account, regenerated following intentional exposure to focused beams of a radiation lethal to Time Lords consequent to the Rani's attack on the TARDIS in order to foil a plot by the Valeyard.	AUDIO: The Brink of Death
	Seventh Doctor	Following a non-fatal shooting, the Doctor was taken to a San Francisco hospital, where subsequent exploratory surgery by Grace Holloway with a camera accidentally clogged a vein; the anaesthetic he had been given delayed regeneration for several hours.	TV: Doctor Who
		In an alternate timeline in which the Nazis won World War II, the Seventh Doctor was gunned down by Nazi soldiers, and regenerated into an alternate eighth incarnation.	AUDIO: Klein's Story
	Eighth Doctor	Died after a ship he was in crash-landed on Karn, but was resurrected for four minutes by the Sisterhood of Karn. After his four minutes were up, he regenerated after drinking from a chalice which Ohila told him she had prepared herself to guide his change towards the form of a "warrior". Ohila would later claim that the drink she gave him was just lemonade and dry ice, and her "moment of theatre" was simply an act to trick him into regenerating.	TV: The Night of the Doctor PROSE: The Day of the Doctor
		In an account where he never regenerated on Karn, the Eighth Doctor instead regenerated from injuries he had sustained from activating the Moment, with assistance from the Restoration.	PROSE: Doctor Who and the Time War
	"Listless-looking" ninth Doctor	In a possible future for the Eighth Doctor (PROSE: The Tomorrow Windows) where the Doctor's ninth incarnation was a "listless-looking" man who prepared to marry his companion, he was killed by a Dalek gunstick blast intended for the Master.	TV: The Curse of Fatal Death
	"Quite Handsome" Doctor	Injured attempting to repair the Daleks' Zectronic Beam Controller while hiding from Emma and the Master.
	"Shy" Doctor
	"Handsome" Doctor	Hit by a discharge of pure zectronic energy, which was believed to have destroyed his regenerative ability. However, the Doctor was nevertheless able to regenerate into his next incarnation.
	War Doctor	Regenerated from his body "wearing a bit thin".	TV: The Day of the Doctor
	Ninth Doctor	Directly absorbed the heart of the TARDIS, and the energies of the Time Vortex itself, from the Bad Wolf to save the life of Rose Tyler, causing "every cell in his body" to die.	TV: The Parting of the Ways
	Tenth Doctor	Grazed by the blast from a Dalek gun stick, causing a regeneration. However, the Doctor directed the regeneration energy to his severed hand, aborting a full regeneration by healing the damage he had sustained before needing to change bodies. This resulted, later down the line, in the creation of a meta-crisis Tenth Doctor and of the DoctorDonna.	TV: The Stolen Earth TV: Journey's End
		Radiation poisoning intentionally incurred in order to save the life of Wilfred Mott.	TV: The End of Time
	Eleventh Doctor	Believed to be near death from old age, a new regeneration cycle granted by the Time Lords automatically triggered a regeneration.	TV: The Time of the Doctor
	Twelfth Doctor	Electrocuted by a CyberMondan, but delayed the regenerative process. Later shot repeatedly by another Cyberman and caught in a massive explosion, triggering the regeneration further. The regeneration was purposely delayed because he desired to not change again, only accepting the change after a meeting with the First Doctor.	TV: The Doctor Falls TV: Twice Upon a Time
	Thirteenth Doctor	Mortally wounded by the Qurunx's destruction beam after it was redirected towards her by the Spy Master.	TV: The Power of the Doctor
	Fourteenth Doctor	Shot by the Toymaker using a Galvanic Beam at UNIT HQ. Unusually, this triggered a bi-generation, causing the Fourteenth and Fifteenth Doctors to exist as separate entities.	TV: The Giggle
	"Previous Doctor"	Regenerated into a new incarnation after being attacked on Karn while on a mission for the Time Lords.	AUDIO: Seven Keys to Doomsday
	"Previous Doctor"	Regenerated into a new incarnation after being shot in the back shortly after a meeting with Mestizer.	PROSE: The Cabinet of Light

The Master

Though the Master famously stole bodies from others, they did also regenerate, many times. By most accounts, they were on their last incarnation when they began body snatching. Later on, the Master was granted a new regeneration cycle.

Individual	Incarnation	Details	Sources
The Master	"Koschei of the Darkheart"	Died from falling into a black hole, forsaking the name of "Koschei" in his last moments and vowing to become "the Master" in his new life.	PROSE: The Dark Path
	Unknown	Drowned.	AUDIO: The Long Despair
	First Monk	In an account where he was an incarnation of the Master, at least according to the Celestial Intervention Agency, the First Monk was shot by the Daleks following his failure in the Kembel Master-Plan.	PROSE: CIA File Extracts
	The War Chief	According to some accounts in which he was an early incarnation of the Master, the War Chief escaped the Time Lords in his TARDIS after being shot by the War Lord's personal guards. They would next pick up his trail on Earth, by which time he appeared as an older man with a graying beard.	PROSE: Doctor Who and the Terror of the Autons
		According to another account, which did not specify the War Chief as a past incarnation of the Master, after being shot by the War Lord, the War Chief managed a partial regeneration into a deformed incarnation who called himself "Felix Kriegsleiter" during his activities in 1940s Germany, and continued to help the War Lord's people. His regenerative process then became "stuck", but Ace later saw it kickstarting again as the War Chief stood in a burning building.	PROSE: Timewyrm: Exodus
	"Penultimate" Master	According to one account, the Master was hit by a blast of artron energy when his attempt to attack the Twelfth Doctor backfired, and he subsequently regenerated.	COMIC: Doorway to Hell
		According to other accounts, he never properly regenerated, reemerging directly as the disfigured Decayed Master either from walking through a time corridor unprotected, or after being shot with his own Tissue Compression Eliminator by Susan Campbell while holding a Dalek transmutation device.	PROSE: CIA File Extracts PROSE: Legacy of the Daleks
	Thirteenth Master	According to one account, the last incarnation of the Master's original cycle attempted to regenerate after sustaining deadly injuries, but, as he had no more regenerations, the process backfired, leaving him a disfigured ghoul.	PROSE: Meet Missy!
	Decayed Master	Used the power of the Eye of Harmony to partially heal himself, altering his voice and facial appearance but still leaving him skeletal.	TV: The Deadly Assassin, AUDIO: Trail of the White Worm
		Used the power of the Keeper of Traken to merge with Consul Tremas of Traken, a process which the resultant Master later described as "not exactly" a regeneration to the Third Doctor, though the Fifth Doctor would later refer to this as a regeneration.	TV: The Keeper of Traken
	Tremas Master	According to one account, after the body of Tremas was stripped from him by the Time Lords, a non-corporeal Master properly regenerated back into a Gallifreyan body with the appearance of his "Tremas" incarnation using regeneration energy stolen from his own past selves.	PROSE: The Velvet Dark
		According to one account, after having his Tremas form converted into a genetically-accurate Gallifreyan body using Tzun nanites, the Master was shot by Ace, and regenerated into a new incarnation.	PROSE: First Frontier
	Old Master	According to one account, pulled himself back together from his ashes as a Deathworm Morphant after being exterminated by the Daleks.	TV: Doctor Who
	Decayed Master	After gaining many new bodies through Deathworm Morphant-aided body theft as opposed to any kind of regeneration, the Master was reverted to his decaying form and died, but ultimately gained a new regeneration cycle from his other incarnations.	AUDIO: Day of the Master
	War Master	In one later-aborted timeline, regenerated during the Last Great Time War of unknown causes into a childlike, but inwardly cunning, incarnation.	COMIC: The Organ Grinder, Fast Sleep
		Shot by Chantho after returning to his proper identity after years living as Professor Yana under the Chameleon Arch.	TV: Utopia
	Saxon Master	According to one account, mortally wounded while fighting Rassilon.	PROSE: Pandoric's Box
		According to another account, the Master was stabbed in the back with a hidden dagger by his next incarnation in such a precise way that he had time to reach his TARDIS before regenerating.	TV: The Doctor Falls
	Missy	Shot by the Saxon Master in a manner preventing normal regeneration, but managed to survive by creating an Elysian field to "kick start a new regeneration cycle". The process of cryogenetic extraction destroyed her body, but retained a copy of her consciousness before regeneration, though casting out most of the "darkness" in her soul.	TV: The Doctor Falls AUDIO: The Lumiat
	The Lumiat	Shot by Missy after she "[grew] bored" of her, and was forced to regenerate.	AUDIO: The Lumiat

Borusa

Individual	Incarnation	Details	Sources
Borusa	Unspecified incarnations between the Decayed Master's meddling with the Eye of Harmony and the Fourth Doctor's adventure opposite the Krikkitmen.	Regenerating after being killed by a falling stack of books.	PROSE: Doctor Who and the Krikkitmen
		Regenerated in a way somehow caused by a missing decimal point.
		Regenerated due to an infected toenail.
	One President Borusa	Regenerated due to the stress of the office of Lord President into a stubborn and grandiose incarnation who sought immortality in the Tomb of Rassilon.	PROSE: The Legacy of Gallifrey
	"Tomb of Rassilon" Borusa	Was freed by Rassilon from the Tomb, and reverted back to an earlier, more stable incarnation in the process.	PROSE: The Eight Doctors

Romana

Individual	Incarnation	Details	Sources
Romana	Romana I	Regenerated into Romana II after appearing to "try on" several possible appearances inside the Doctor's TARDIS.	TV: Destiny of the Daleks
		According to one account, unbeknownst to the Doctor, Romana I had been harmed by the Key to Time, and she regenerated inside a force field hidden away, while the "possible Romanas" the Doctor saw were projections of the TARDIS.	PROSE: The Lying Old Witch in the Wardrobe
		According to other accounts, Romana I regenerated willingly "for the fun of it".	PROSE: City of Death
		According to yet another account, she triggered a regeneration to try and purge the influence of Pandora from her mind.	AUDIO: Lies
	Romana II	According to one account, regenerated in preparation for the War in Heaven, adopting a body and attitude more suited for combat as the War Queen Romana III.	PROSE: The Shadows of Avalon
		In another account, Romana II started to regenerate into a different third incarnation due to contact with the decaying Eye of Harmony inside the Matrix, interacting with a projection thereof inside the Matrix. However, this regeneration didn't take hold due to K9 Mark II removing her from the Matrix in time.	AUDIO: Renaissance, Ascension
		In an aborted timeline, Romana II regenerated to give a power boost to the Moros engine shields in order to stop a black hole being formed. This regeneration was prevented by Irving Braxiatel due to the potential third incarnation wanting to stop the Omega war.	AUDIO: Enemy Lines
	Romana III	After using a psychic attack on Ofrin, an elderly form of the Romana III who had led Gallifrey in the War in Heaven died of exposure to the elements on an unnamed planet near the heat death of the universe and regenerated into a new, dark-skinned incarnation.	PROSE: Tomb of Valdemar

Rassilon

Individual	Incarnation	Details	Sources
Rassilon	First incarnation	According to one account, Rassilon regenerated for the first time following accelerated ageing due to the temporal radiation of the Eye of Harmony's elemental forces and the stress of the situation he was in.	PROSE: The Legacy of Gallifrey
	Resurrected Rassilon	Following his resurrection in the Last Great Time War, Rassilon was wounded by the Sicari, who had been allowed in Gallifrey by Romana II and the War Livia Caralis, and was forced to regenerate.	AUDIO: Assassins
	"Final Day" Rassilon	Attacked by the Saxon Master, who "stuffed his face full of White-Point Stars," causing Rassilon to regenerate.	PROSE: Lords and Masters

Other Time Lords

Individual	Incarnation	Details	Sources
The Hermit	K'anpo	Attacked by the Eight Legs on Earth. He regenerated into Cho-Je, who had previously been active as a projection from his own mind.	TV: Planet of the Spiders
Pavo	Unnumbered incarnation	The male Constable Pavo was shot by the Monk, who used a perception-altering ring to pose as Pavo, while Pavo regenerated into a female incarnation with the aid of the Second Doctor and Jamie McCrimmon.	AUDIO: The Black Hole
Ailla	Unnumbered incarnation	Accidentally shot by Koschei while he was fighting with Imperial forces in the Darkheart; although badly injured and apparently dead due to assuming that she was only human, she was able to survive in her damaged body until she returned to Koschei's TARDIS and regenerated in the Zero Room.	PROSE: The Dark Path
Rallon	First incarnation	Initiated all twelve of his regenerations at once to force the Celestial Toymaker out of his body; his previously-manifested Watcher subsequently merged with the Toymaker to keep him in check in the future, the Fifth Doctor noting that this would mean that the Toymaker himself had essentially regenerated as a person.	PROSE: Divided Loyalties
Roche	Unnumbered incarnation	Caught in a traffic accident while on Earth; he retained enough control over the process after it began to deliberately shape his new appearance so that he was the exact duplicate of the Third Doctor.	PROSE: The Suns of Caresh
Tauras	Unnumbered incarnation	Attempting to free Omega from his anti-matter universe, Tauras regenerated after he was shot by Narvin.	AUDIO: Intervention Earth
Janartis	Unnumbered incarnation	Attacked by pig-rats and K9's stun laser and forced to regenerate. But, because he was infected by the Dogma Virus, he became a pawn for Free Time.	AUDIO: Panacea
Azmael	Thirteenth Azmael	In his thirteenth and final body, Azmael deliberately regenerated past his limit, killing himself, but also Mestor, who had been attempting to possess Azmael's body after his own was destroyed.	TV: The Twin Dilemma
Iris Wildthyme	"Beryl Reid" Iris	Regenerated into the "Jane Fonda" Iris after a lengthy illness caused by eating a Dalek mutant raw.	PROSE: The Scarlet Empress
Unnamed Renegade	The Eight	Badly injured while helping the Eighth Doctor and River Song resist a telepathic attack from the Clocksmith, he went into the Doctor's TARDIS and regenerated into the Nine.	AUDIO: The Doomsday Chronometer
	The Eleven	Killed when he attempted to propose an alliance between himself and three incarnations of the Master after the failure of his prior alliance with the Ravenous; denouncing the Eleven as a twisted lunatic, the three Masters shot him and expelled him from their TARDIS with only a vortex manipulator, whereupon he regenerated into the Twelve.	AUDIO: Day of the Master
Verne	Fifth-to-last incarnation	After voting for the side opposing those who had sponsored his rise to power, Verne was caught up in a fight and was so badly injured that he was forced to regenerate into an incarnation that had a plain face and a laughably high voice.	PROSE: The Twin Dilemma
	Fourth-to-last incarnation	Willed himself to regenerate again immediately after his previous regeneration, finding his new body less than satisfactory — resulting in a body that was a deformed, elderly man.
	Third-to-last incarnation	Willed himself to regenerate again immediately after his previous regeneration, finding his new body less than satisfactory — resulting in a body that was an amorphous blob.
	Second-to-last incarnation	Willed himself to regenerate again immediately after his previous regeneration, finding his body less than satisfactory — resulting in a monstrous inhuman form which the Lord President had destroyed.
High Tutor Albrecht	Unnumbered incarnation	Regenerated as a result of an experiment by Theta Sigma involving a perigosto stick and a temporal feedback loop	PROSE: The Time Lord Letters
Intrepid	First incarnation	Intrepid's first body failed at an unusually young age because, as a human-Homeworder hybrid, "her body was fighting itself". She was thus forced to "renew" herself.	PROSE: Going Once, Going Twice
Unnamed House Military member	Second-to-last incarnation	Regenerated against her will into a monstrous form after receiving mortal wounds to her stomach at the Battle of Cratosi Fields. The resulting incarnation was erased from time alongside everything else at the First Auction in Heaven.
Kallix	Unnumbered incarnation	Regenerated after the Daleks attacked the Neverwhen.	AUDIO: The Neverwhen
Trave	Female incarnation	Shot by Gaal after finding out he was a traitor at Outpost Delta.	AUDIO: Enemy Lines
Larissa	Unnumbered incarnation	Regenerated after being shot in the abdomen by Doctor Bendo.	PROSE: Newtons Sleep
Chatelaine Thessalia	Imperator Presidency-era incarnation	Forced herself to regenerate after the Imperator's trial by putting a gun in her mouth and committing suicide.	PROSE: The Book of the War, Newtons Sleep
	Unnumbered incarnation	Regenerated again, growing younger and taller, sometime before recruiting Larissa to the Order of the Weal. Larissa speculated this occurred during the worldquake or the goblin infestation.	PROSE: Newtons Sleep
The General	Eleventh General	After tricking the Time Lords into saving Clara Oswald with an extraction chamber, the Twelfth Doctor tried to flee with Clara and armed himself with the General's sidearm. As the gun had no stun setting, the Doctor shot the General, though only after he confirmed that he had not yet completed his regeneration cycle. The shot resulted in the General's immediate regeneration.	TV: Hell Bent
Ollistra	Unnumbered incarnation	Pushed off a building in New York City by the Eleven.	AUDIO: The Side of the Angels
Karlax	Unnumbered incarnation	Forced to regenerate by being exposed to the space vacuum after Dalek stealth ships destroyed his Battle TARDIS during the Last Great Time War.	PROSE: Engines of War
Ruath	Second incarnation	Drained every drop of her own blood from her body to restore Vampire Lord Yarven. Yarven subsequently turned her new incarnation into a vampire.	PROSE: Goth Opera
Ophiuchus	Unnumbered incarnation	Dying from an unknown cause, Ophiuchus was saved by the Fifth Doctor, who gave him a "little push" having been convinced by Nyssa and Tegan and regenerated.	COMIC: Ophiuchus
Innocet	Unnumbered incarnation	After staying in the same body for over six hundred years, Innocet was killed by a Quences-possessed Badger to protect the Doctor and regenerated into a new, younger incarnation.	PROSE: Lungbarrow
Glospin	Unnumbered incarnation	Force-regenerated himself into the double of the First Doctor after acquiring a genetic sample to influence the appearance of his next incarnation.
	"First Doctor" incarnation	Having killed Quences while disguised as the Doctor, Glospin regenerated again to conceal his role in the murder.
Cavis	Last incarnation	Began to regenerate after she was decapitated by Queen Regent Mab, although Mab stabbed her in both hearts, halting the process and ensuring that Cavis stayed dead.	PROSE: The Shadows of Avalon
Gandar	Unnumbered incarnation	Stabbed in the heart by Margwyn, but regenerated as Margwyn missed his second heart.
	Unnumbered incarnation	Gandar regenerated again shortly after his previous regeneration when he received a fatal sword wound; his new incarnation resembled a hybrid of human and Silurian and was far more peaceful than his previous violent selves.
Epsilon Delta	First incarnation	A run-in with some Sontarans triggered Epsilon Delta's first regeneration.	PROSE: The Dimension Riders
Louis	First incarnation	Louis' first regeneration was triggered by a staser-gun blast inflicted by Rigan.	AUDIO: Unregenerate!
Surgeon-Master Elbon	Unnumbered incarnation	Shot by a servitor that Irving Braxiatel placed in the TARDIS that Romana II used whilst trying to bring a pair of Pig-rats back to Gallifrey. His next incarnation was hijacked by the Dogma Virus.	AUDIO: Panacea
The Minister	Unnumbered incarnation	Assassinated while under the name of Prime Minister Felicity Morgan.	AUDIO: The Same Face
Andred	Unnumbered incarnation	Badly wounded after a shootout with Torvald.	AUDIO: A Blind Eye

Parallel universes

Individual	Incarnation	Details	Sources
"Inferno Earth" counterpart to the Doctor	"Inferno Earth" Second Doctor	Forced to change his appearance for the same reasons as his N-Space counterpart. Unlike his counterpart, however, he picked one of the faces the Time Lords offered him.	PROSE: Timewyrm: Revelation
Unbound Universe counterpart to the Master	"Exiled" Unbound Master	Wounded in a plane crash and regenerated into his next incarnation due to his injuries.	AUDIO: Sympathy for the Devil
"DEEP universe" counterpart to the Doctor	The Doctor	Had his neck broken by General Flint.	AUDIO: Full Fathom Five
	New Doctor	Emerged from his regeneration only to be immediately shot dead by Ruth Mills.
"Exile Universe" counterpart to the Doctor	"Previous Doctor"	Committed suicide by jumping off of a pylon to escape the Time Lords. His next incarnation was a woman.	AUDIO: Exile
The Warrior's universe counterpart to the Doctor	Fourth Doctor	Exterminated by a surviving prototype Dalek after averting the creation of the Daleks. His next incarnation fought in a Time War and chose to abandon the tile of "the Doctor", so he was known as the Warrior.	AUDIO: Dust Devil

Other regenerating individuals

N-Space

Individual	Incarnation	Details	Sources
I.M. Foreman	First twelve incarnations	As a priest, I.M. Foreman had been given the gift of regenerations. This made twelve different individuals, who were created by his body absorbing the DNA around him; all regenerations were caused by the Third Doctor sending Foreman's first twelve bodies back to Gallifrey's past so that they fell from a great height, each regenerating into their next body, the trauma of the regeneration causing each incarnation to lose their memories.	PROSE: Interference - Book One, Interference - Book Two
K9	K9 Mark I	Regenerated into K9 Mark 2 using his regeneration unit after being forced to self-destruct to protect some humans from Jixen warriors.	TV: Regeneration
Melody Pond	"The Little Girl"	As a little girl, Melody regenerated on the streets of New York City in 1970 due to a terminal illness.	TV: Day of the Moon
	Mels Zucker	Regenerated in Adolf Hitler's private study in 1938 after Hitler accidentally shot her while aiming for the Teselecta.	TV: Let's Kill Hitler
Supreme Dalek and other Daleks in the Dalek City, including in the sewers	Ageing original bodies	Regenerated into healthier, "more powerful" forms within their casings after Davros drained massive amounts of regeneration energy from the Twelfth Doctor with the help of Colony Sarff and transmitted them into the hearts of every Dalek on Skaro.	TV: The Witch's Familiar
Brooke	Brooke 1	Brook 1 regenerated for the first time after being shot by River Song.	AUDIO: My Dinner with Andrew
Lake	Lake 1	Lake's first regeneration was induced after he was mortally wounded by an unstable fuel cell.	AUDIO: The Lady in the lake
	Lake 2	Willfully regenerated to test his ability to consciously base his appearance on people he had met before.
	Lake 3	Shot by River Song in revenge for his having killed Lily, who, unbeknownst to both of them, was his own future self, and he regenerated into Lily.
Wadi	All incarnations	Wadi's regenerations were all expended through fatal injuries inflicted by Lake.
Stream	Multiple incarnations	As part of his religious cult, convinced by Lake to die multiple times on Terminus Prime so he could covertly study regeneration and find out how many times Proto-Time Lords like himself were able to regenerate.
Beck
Creek
Rindle	First incarnation	Regenerated after being mortally wounded by a wild beast.
	Second incarnation	Regenerated after being killed by Lake.
	Third incarnation	Had her remaining regenerations drained by Lake to power his ship.
Tarn	First eleven incarnations	Deceived by Lake into believing that regeneration was a constant rebirth, Tarn went to Terminus Prime to commit suicide so he could continually be born again. By the time he met River, he had already died eight times. He was killed again by Kevin and then again by Dave, regenerating at least ten times.
A CyberMaster	First CyberMaster incarnation	Shot by one of its fellow newly-created CyberMasters on the order of the Spy Master, so as to "test out" the regenerative abilities of the new species in front of the Thirteenth Doctor.	TV: The Timeless Children
Swarm	Old Swarm	Triggered a regeneration from his old, decrepit body into the Younger Swarm by absorbing En Sentac's life force	TV: The Halloween Apocalypse
Malika	First incarnation	Sentenced to death by firing squad by Oxirgi.	COMIC: Omega, AUDIO: Omega
	Second incarnation