Baltazar

Baltazar was the main villain in The Infinite Quest. He was after the Infinite, and used the Doctor to track it down. He had a metal bird pet called Caw. He was a space pirate, and was once imprisoned on Volag Nok.

Trvia
The Doctor calls him the "scourge of the galaxy", but he previously used that title for the Macra. (DW: Gridlock)