Sylvester the cat

Sylvester is a fictional cat who appears in several Looney Tunes cartoons, often chasing Tweety Bird, Speedy Gonzalez, or Hippety Hopper. Sylvester's trademark was his sloppy, stridulating lisp (which, like Daffy Duck's, was based on producer Leon Schlesinger's).

Sylvester was definitely on the "loser" side of the Looney Tunes winner/loser hierarchy. His character was basically that of Wile E. Coyote while he was chasing mice or birds. He shows a different character when paired with Porky Pig in explorations of spooky places (in these cartoons, he basically plays the terrified Costello to Porky's oblivious Abbott.) Sylvester's most developed role is as hapless mouse-catching instructor to his dubious son, in which the "mouse" is a powerful baby kangaroo. His alternately confident and bewildered episodes bring his son to shame, while Sylvester himself is reduced to nervous breakdowns.

His voice was provied by voice acting legend Mel Blanc. The character was original named Thomas.