Bugs Bunny comes to a city park to be daily fed carrots by a meek, little man. Bugs proposes that the man adopt him as a pet. The man accepts and takes Bugs home, where he states he is a doctor - and the name on his shingle is Dr. Jekyll. Unbeknownst to Bugs, Jekyll gives into the temptation to drink his potion that changes him into Mr. Hyde. Bugs keeps fleeing Hyde and running to the re-transformed Jekyll for help, but behind Bugs' back, Jekyll involuntarily changes back into Hyde. Bugs helps himself to some of Jekyll's potion before leaving to return to the park, where he changes into a shaggy, green rabbit that scares everyone away.