With Mr. Krupp gone and two terrible Melvins in charge, Harold and George fight back by hypnotizing their gym teacher, Mr. Meaner.

The boys recruit kids to join the M.I.S.F.A.R.T.S. -- the Mega Incredible Search Force Adventure Rescue Team Squad -- and bring Mr. Krupp back to School.

After injecting all the teachers with bee DNA, the Melvins run the new "hive mind" of the school -- until Ms. Ribble accidentally becomes queen bee.

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!

Who knew a thawed-out dinosaur could read comics and pull pranks? Well, this one does -- and he's one of Harold and George's biggest fans.

Captain Underpants becomes a wanted man when a criminal who looks just like him starts robbing banks. Can George and Harold help clear his name?

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!

After George and Harold work with Erica to create a new comic book hero, she springs off the page -- and plunges into real-life crime fighting.

Harold and George can't wait to spend the summer together at camp. But not so fast, boys -- your old nemesis Mr. Krupp has a most unpleasant surprise.

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

Eager to get the campers out of his hair, Krupp orders them to climb Plummet Peak, where a terrifying creature is rumored to reside.

Harold and George don't ask for much -- just a fun scavenger hunt that doesn't include doing Krupp's errands. Careful what you wish for, fellas.

A run-of-the-mill arts and crafts session turns into an interdimensional adventure from which Harold, George and company may never return.

Krupp's campers take on rich rivals in a hoity-toity boat race that also features a revenge-obsessed giant salamander. Paging Captain Underpants!

The campers' splat-tastic game of paintball is rather rudely interrupted by a foul and formidable fiend known only as Camoflush.

With fun in short supply, Harold and George persuade Krupp to dump the campers in the middle of the forest so they can learn to rough it.