After Morka killed Okdel, K'to assisted him in releasing the Silurian virus to wipe out humanity.
When the Third Doctor tricked them into going back into hibernation, Morka, who decided to stay behind to ensure the hibernation process went underway, made K'to leader. However, shortly afterwards, K'to, Morka and the surviving Silurians were killed when UNIT blew up the Silurians' base. (TV: Doctor Who and the Silurians)
K'to was not named on-screen, only in the novelisation and in the novel The Scales of Injustice. The Scales of Injustice gives him the full name Bokka K'to. He was listed as "Silurian Scientist" in the credits.