Shoal droid

The Shoal droids were robotic droids designed to look like members of the Shoal of the Winter Harmony. One half of their head was humanoid in appearance, whilst the other half was open and had an exposed homing beacon.

The Doctor and Nardole encountered two of the droids on the Shoal spaceship. The droids acted like security guards and tried to attack the pair. (TV: The Return of Doctor Mysterio)