Mortakk

Mortakk was noted as the blackest character in Silurian history in a parallel version of Earth.

Biography
Mortakk's crimes included conducting genetic experiments on both Silurians and Sea Devils. He was tried and believed to have been executed before the great hibernation. However, his base was located in an abandoned nuclear research centre at Darkmoor and the Seventh Doctor, along with Bernice Summerfield and the Silurian scientist Thactus of URIC, travelled in the TARDIS to confront him.

Mortakk had indeed survived. He created a gas with mutagenic properties that forced Silurians or humans to evolve into hybrid creatures with both reptilian and mammalian qualities. This brought him into conflict with his enemies. Mortakk fought the Doctor in a sealed room where the gas was released. Due to his Gallifreyan biology, the Doctor was not affected and Mortakk was killed in the battle. (DWM: Final Genesis)


 * It is not known whether Mortakk existed within the mainstream Earth.