Avanonion

From Tardis Wiki, the free Doctor Who reference

The Avanonions were a species thought to be long-extinct. Bernice Summerfield led an expedition to find out more about their civilisation. She and the members of her group discovered that the Avanonions reproduced by harvesting the DNA from other species, but they had evolved into chicken-like, non-sapient animals by the time of Benny's arrival on their planet. (PROSE: Cuckoo)