Warren T. Rat

Warren T. Rat 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".

Personality
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).

He also shows no qualm in tormenting others, as Reese had always been a thorn to his plans, on mostly him attempting to talk Fievel out of trusting Warren when they first met, Warren takes this to an advantage and torments Reese off screen, but Fievel rescues him before the painful procedure could begin.

An American Tail
He offers false friendship to Fievel Mousekewitz, when the two meet, much to the protests of Reese and offers to take him to his missing family - yet after gaining Fievel's trust he cruelly sells both him and Reese to a sweatshop, when next they meet it is some time after Fievel and Reese managed to escape the sweat-shop: they sees Warren T for what he truly is, a cat, and is imprisoned by Warren T, except for Reese for whom he tells the cats "To have Fun with him". Reese is tormented off screen, 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, and Fievel ventures to the deep portions of the lair where he is able to find and successfully rescue Reese before escaping back to the surface.

Warren T and his gang give chase to both Reese and 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 for China along with his gang.

Trivia

 * Warren was to be originally used for Banjo the Woodpile Cat as a character named Rocko. Unfortunately, this idea along with a termite (alot 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...