After Erica critiques their comic book, George and Harold create a brand-new character -- a vampire who sucks the joy out of everything.

Holy guacamole! George and Harold are so determined to win an avocado-growing contest that they accidentally turn their science teacher into a monster.

The boys' latest comic inspires their jorts-wearing Spanish teacher to become a superhero with otherworldly powers.

The boys travel back in time to stop Mr. Krupp from becoming a bully, only to find that their plan has turned him into a ruthless businessman.

It's a race against time as George and Harold try to get Mr. Krupp fired before he can have them expelled. But first: a faceoff with the Toot Fairy!

George and Harold train a rat for extra credit. But when their subject escapes into the sewers, he's doused with toxic waste and becomes ... Poopacabra!

The boys use Melvin's new animal hybrid invention to make a creature that's a cross between a butt and a fly. But these butt-erflies are real monsters!

George and Harold trick Melvin into turning their bus into a time machine so they can reroute their field trip and see what ancient Rome was really like.

Stuck in separate camps, Harold and George unleash a hyperintelligent talking possum to scare the pants off of Krupp. What could possibly go wrong?