When their class tadpoles are big enough, Mr. Stricter tells his students they can keep just one. The class chooses Bruno, the smallest of the bunch. But Bruno doesn't stay that way for long. Soon, he's grown into a giant, classroom-wrecking creature: he eats desks, he farts for show-and-tell, and he sneezes slime all over everything! With Mr. Stricter blinded by love for the pet, the students must step up and take matters into their own heroic hands.