Mad Doctor

The Mad Doctor is the main villain of the 1933 short of the same name. He wanted to attach Pluto's head to the body of a chicken in order to "find out if the end result will bark or crow or cackle".

Epic Mickey
Years ago, when the Mad Doctor arrived in Wasteland, his immediate priority was to seek power. Becoming a close partner to Oswald, he constructed the Beetleworx as a construction crew to help improve the land as new arrivals came in. But when Mickey created the Phantom Blot and the Blot Wars began, he quickly switched sides and became Blot's closest ally. He offers the Blot the opportunity to become a beloved cartoon star in his own right, the desire of all cartoon characters, and sets his plot into motion to drag Mickey back into Wasteland and set him and Oswald against each other. He is later shown to be a auto-animatronic, this is so when the Blot sucks the paint out of Wasteland, only the animatronics would servive, and he would be their ruler.

Personality
As his name suggests, the Mad Doctor is very murderously insane and takes much joy in causeing harm to others, but makes up for it at being a scientific genius. His work always consist of dark cutting machinery and various other contraptions, most of which are used in his deadly expiraments; though some of his gadget have served a perpose as the Beetleworx was at one point a construction crew. In Epic Mickey his personality is expanded, though insane, he is also very conniving and manipulative as he uses the jealousy of Oswald to destract Mickey as he works closely with the Phantom Blot (who he is also useing for his own perposes). It is even shown that when he was working for Oswald in Epic Mickey: Tales from the Wasteland that while seemingly trying to help the rabbit is really waiting for the right time turn on him and take control of Wasteland.