Harpy

Harpies were a species that tried to invade planets so they could feed. (COMIC: The Warkeeper's Crown)

Biology
They were able to switch between their real forms and a human form. In their real forms, they were significantly larger than humans, had red skin, and wings which enabled them to fly. (COMIC: The Warkeeper's Crown)

History
A group of four harpies, in the disguise of nursemaids on the Slough of the Disunited Planets, tried to use the Warkeeper's Crown to control the Hawk army and win wars. They killed the original Warkeeper and replaced him with Michael Yates. They transported themselves to Upper Wardleswick on Earth, where Yates declared he would invade France. They were defeated by the Tenth Doctor and the Brigadier. (COMIC: The Warkeeper's Crown)