Looney Tunes

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.