Bokka K'to

K'to was a member of the Silurian triad of Wenley Moor, which included Morka and Okdel. After Morka killed Okdel, K'to assisted him in releasing the Silurian virus to wipe out humanity. K'to was killed when UNIT blew up the Silurians' base. (DW: Doctor Who and the Silurians)

Behind the scenes
K'to was not named on-screen, only in the novelisation and in MA: The Scales of Injustice. He was listed as Silurian Scientist in the credits.