Billie Davis
From Tardis Wiki, the free Doctor Who reference
Billie Davis had an uncredited role as a member of the Tribe of Gum in the Doctor Who television story An Unearthly Child. (DWMS Summer 1994)
According to the Internet Movie Database, the Billie Davis who appeared in the story was the Surrey-born female pop singer who had (in 1963) recently enjoyed a major hit with her record "Tell Him". However, the more authoritative DVD Production Notes for An Unearthly Child indicate that the Billie Davis who appears in the story was actually a male actor cast as one of the tribesmen.