 As Sylvester naps on the ledge of a high-rise building, he awakens to see Dr. Jekyll drink his infamous formula and change into a hideous monster. Falling back to sleep, Sylvester begins dreaming he s chasing Tweety Bird, who escapes into Dr. Jekyll s lab and takes refuge inside the jug containing the Hyde formula. The formula changes the innocent little canary into a monstorous bird of prey that immediately begins stalking the puddy tat. Tweety repeately changes from his normal self into the bird-monster, with Sylvester chasing the canary and fleeing from the Hyde-bird. Eventually, Sylvester catches Tweety and (apparently not knowing Tweety and the Hyde-bird are one and the same) locks himself and the bird into a small, windowless room. Sylvester turns his back to search a cupboard for condiments for "that Tweety sandwich I ve been dreaming about," but Tweety morphs into his monstorous self; the bird quickly devours the puddy whole! Just as Sylvester fruitlessly tries to flee his stalker, the puddy awakens from his dream, only to spot Tweety flying precariously to the ledge. Sylvester screams and flees in terror, crashing through a brick wall.