The Headhunter was a bounty hunter.
The Headhunter was hired by Todd Hulbert to recover Lucie Miller. (AUDIO: Blood of the Daleks) The Eighth Doctor and Lucie had a number of near encounters with the Headhunter: she arrived at the Nadir Motorway Service Station in 1974 shortly after they departure, (AUDIO: Horror of Glam Rock) arrived on Phobos days before the duo, fell off a bicycle, knocked herself out and didn't regain consciousness until they had left, (AUDIO: Phobos) and finally arrived just in time to snatch Lucie from a country house in 2006. (AUDIO: No More Lies) The Headhunter was contracted to capture Lucie and used her own time travel technology to track the Doctor's TARDIS. (AUDIO: Human Resources)
The Headhunter and Karen Coltraine travelled to 19th century Sweden, where her plan of destroying a pocket universe was stopped by Lucie and the Doctor. (AUDIO: Grand Theft Cosmos) After the Time Lords took Lucie home, she kidnapped Lucie from her home in Blackpool using a Time Bullet. (AUDIO: The Vengeance of Morbius) She later obtained the Doctor's TARDIS from the Sisterhood of Karn, and attempted to blackmail the Doctor into selling it to her in order to spare Lucie's life. (AUDIO: Orbis)
The Headhunter was hired by the Eight Legs to place several Metebelis crystals in Yorkshire in the 21st century. (AUDIO: Worldwide Web) She then became part of their plan to possess every being in the universe, supplying them with technology to further their plans. (AUDIO: The Eight Truths) When the Eight Legs' plan began to fail due to the intervention of the Doctor, the Great One jumped on to the Headhunter's back. The Headhunter tricked the Great One into falling for its own hypnotic spell, causing it to die, taking the Headhunter with it. (AUDIO: Worldwide Web)