Vidler

Vidler was one of only a handful of humans left alive on the Phoenix colony - the colony's leader, Auntie, had allowed the reptilian Khellians to feed off the colonists in exchange for sparing her family. Vidler was always a natural rebel, bent on defying the colony's policy of individual isolation, and when the Fifth Doctor and his companions arrived, Vidler was perfectly positioned to help them get to the bottom of the mystery. (BFA: Three's a Crowd)