Warren T. Rat (real named as Warren T. Cat) is the main antagonist of An American Tail. It would later be revealed in the movie that he is really a cat in disguise who leads a group of cats called the Mott Street Maulers, who terrorize the mice of New York City. He is accompanied by a cockroach named Digit. His name may be a play on the word "warranty". He is voiced by the late John P. Finnegan.
He's greedy and he likes to think of himself as sophisticated, constantly misquoting Shakespeare. He also plays the violin horribly (though that might be because his fake nose kept getting in the way).
Role in film
He offers false friendship to Fievel when the two meet and offers to take him to his missing family - yet after gaining Fievel's trust he cruelly sells him to a sweatshop, when next they meet it is some time after Fievel managed to escape the sweat-shop: he sees Warren T for what he truly is, a cat, and is imprisoned by Warren T and his gang to stop him telling anyone, however, Fievel is released by Tiger - a soft-hearted minion who doesn't share the usual anti-mice feelings most cats do in the film.
Warren T and his gang give chase to Fievel but are caught in a trap by the mice, who have had enough of being bullied and unleash a mechanical mouse that proceeds to knock Warren T and his gang off the harbor and into the sea - Warren T was last seen hitching a ride on a boat heading to China along with his gang.
Warren was to be originally used for Banjo the Woodpile Cat as a character named Rocko. Unfortunately, this idea along with a termite (a lot like Digit) who saves Banjo from trouble before meeting Crazy Legs and Banjo being a full-length motion picture were all dumped, due to production costs.