Captain Underpants Wiki

Alright, sonny. Prepare to get your bucket whupped by Boxer Boy and Great-Granny Girdle!
  —Boxer Boy [src]  
Yes, it is, my big strong man.
  —Great-Granny-Girdle [src]  

Great-Granny Girdle and Boxer Boy are the superhero alter egos of the grandparents of George and Harold.


Captain Underpants and the Preposterous Plight of the Purple Potty People[]

George and Harold take the 3-D Hypno-Ring, so that they can de-hypnotize Sulu, and the Extra Strength Super Power Juice just in case. However, Moses Beard stops George and Harold from leaving the house and forces them to come inside, as it is Grandparent's Day. They have to eat dinner with their grandparents at George's house. While George and Harold try to explain to Mr. Beard that they need to leave, George and Harold's grandparents take the remainder of the Extra-Strength Super Power Juice and drink it.

Elsewhere, Evil George and Evil Harold find Good George and Good Harold's treehouse, rummage through their personal belongings and find the Goosy-Grow 4000. They then use it to transform Sulu into a giant monster. Sulu charges at Good George and Good Harold, but Crackers flies in and saves them. Good George and Good Harold flee from their home, flying over on Crackers' back and being chased by Evil Harold, Evil George, and Captain Blunderpants.

Good George and Harold decide that they have to drink the superpower juice to fight back, but unfortunately, they realize it is somehow empty despite there being a sizable amount of juice earlier. Since there was no more of the Super Power Juice left, they decide to travel to Mr. Krupp's house to summon Captain Underpants.

Later, Good George and Good Harold are forced to get away on Crackers while Captain Blunderpants flies after them with Evil George and Evil Harold in his hand. Good George soon finds the Shrinky Pig 2000 in the treehouse, which the gang can use to make the evil twin counterparts no longer a threat.

Unfortunately, it is too late as Captain Blunderpants grabs the duo by their shirts while the device falls into the hands of Evil George and Evil Harold. When all seems lost, George and Harold's grandparents arrive and order Captain Blunderpants to put down their grandchildren, but he just tightens his grip on them. So, George and Harold's grandparents become Great-Granny Girdle and Boxer Boy.

They then place two curtains on them as capes before they defeat Captain Blunderpants and save their grandchildren. Good George notes he figured out what happened to the Super Power Juice that disappeared earlier.

However, Evil George and Evil Harold are prepared to use the Shrinky-Pig 2000 on their alternate twins, but Good Harold claims they can go right ahead as they are holding the device backward. The evil twins believe this and turn the device around before activating it, resulting in themselves being shrunk. After giving the evil twins the punishment they deserve, George and Harold's grandparents fly off for truth, justice, and all that is preshrunk and cottony!