Sh'vak

Sh'vak was one of the Silurians based below the Galápagos Islands. When Tulok was exiled to the surface with his ape creations, she let him back in. Some time after she came out of hibernation, she discovered his betrayal of their clan, and helped the Sixth Doctor to stop Tulok from destroying the human race with a plague. In doing this she exhausted herself and died in the process. (AUDIO: Bloodtide)