Jacob reluctantly agrees to do some volunteer to work at the veterinary clinic of Dr. Leduc, rumored to have a secret laboratory where he conducts strange experiments. Life imitates crazy rumor when, while demonstrating his pet hypnosis technique for Jacob, the well-meaning veterinarian accidentally turns his hulking butler, Monsford, into a snarling animal that is soon terrorizing the city. Jacob befriends the rampaging Monsford, and finds it hard to face the day when he must let his pal go back to life as a butler.