His name's Runt, but his master called him stupid.

Rita and Runt from Animaniacs. Rita and Runt are two homeless characters who almost always appear together. Rita (the cat), usually sings some songs while dim-witted Runt (the dog), listens. Throughout their journey in life, the vagabond pair have many exciting adventures during the segment. Despite having a desire to find a nice permanent new home, the two manage to live quite comfortably by offering each other a close unbreakable friendship in defending one another for protection and giving moral support.