Istervaalan

Istervaalans were a species that had evolved from mountain goats on the planet Intervaal. The Tenth Doctor claimed of the species, "Evolution didn't take a funny old turn there". (NSA: Ghosts of India)

Behind the scenes

The species is simply used for a gag in Ghosts of India, and the Doctor never actually names the species. Thus Istervaalan may only be a demonym rather than a proper species name.