Ohtarian

The Ohtarians are a species of alien that are a common enemy in Doctah Who.

Description
Ohtarians' torso can vary from time to time, usually with more powerful of them wearing more elaborate outfits, but the consistent thing is that they, in their default form, have a face that resembles a bird. They have the ability to take on the form of many different species, and although it is not confirmed how far this ability goes, it is at least known that they can assume the form of Time Lords, as they did with the Mastah. This ability is not limited to disguise: they also assume all abilities of the species they morphed into. The Ohtarian that transformed into the Mastah in The Doctah Falls can be seen regenerating, as a Time Lord would. They are typically weak to The Doctah.

Story
The first time an Ohtarian is seen on the show is in Episode 3, A Code of High Value. The Ohtarian is seen trying to find a way to take over the world, so he Googles it and finds a password protected document, and tries to get the password out of the Doctah. The Doctah sees the Ohtarian as an enemy, and defeats it. This creates an enemy out of the entire alien race of Ohtarians.