Mickey Mouse - The Mad Doctor - No.6

The Mad Doctor is a Mickey Mouse cartoon released in 1933.  It is known as the first appearance of the title character "The Mad Doctor", or "Dr. XXX". 

The plot centers on the title character, a mad scientist who has kidnapped Mickey's dog, Pluto. Mickey tries to rescue him before the doctor can perform his experiment: putting Pluto's head to the body of a chicken in order to see if a puppy will hatch from an egg (that is if the end result will "bark or crow or cackle"). Mickey battles his way through booby traps and animated skeletons before eventually getting caught and strapped onto a table to get cut open by a buzz-saw, forcing Mickey to suck in his belly, trembling. The scene then fades to Mickey asleep in bed and suddenly woken up by a fly, whose buzzing resembles the whirring of the saw. Not yet realizing the events were only a nightmare, Mickey shouts for Pluto, who eagerly jumps onto Mickey's bed with his doghouse and chain still attached to his collar.