In his early appearances in Bob Clampett cartoons, Tweety is a very aggressive character who tries anything to foil his foe, even kicking his enemy when he is down. One of his most notable malicious moments is in the cartoon Birdy and the Beast. A cat chases Tweety by flying until he remembers that cats cannot fly, causing him to fall. Tweety says sympathetically, "Awww, the poor kitty cat! He faw down and go (in a loud, tough, masculine voice) BOOM!!" and then grins mischievously. A similar use of that voice is in A Tale Of Two Kitties when Tweety, wearing an air raid warden's helmet, suddenly yells, "Turn out those lights!" Tweety's aggressive nature was toned down when Friz Freleng started directing the series, with the character turning into a more cutesy bird, usually going about his business, and doing little to thwart Sylvester's ill-conceived plots, allowing them to simply collapse on their own; he became even less aggressive when Granny was introduced, but occasionally Tweety still showed a malicious side.