Squawk

Squawk was a robotic bird from Pharos, who served Baltazar as a spy. His father was Caw, who Squawk later mourned for. Squawk was disguised as a small brooch, given to Martha Jones by Caw. When the TARDIS is hijacked by Baltazar, The Doctor turns Squawk big enough to ride on, and travels to the Infinite to rescue Martha. Squawk took Baltazar to Volag Nok, where he belongs. (DW: The Infinite Quest)