|This article is for the different forms that Rippen takes on missions in different dimensions.|
Forms are sorted in the alphabetical order of the worlds, with unknown/unnamed worlds listed at the bottom.
Normal appearanceWhen he isn't in another dimension, Rippen is tall and muscular with pale green skin. He has black hair with several greenish-gray streaks, along with a goatee, and he has red eyes and pointed ears. He wears a dark purple business suit with light gray sleeve ends and collar, a red tie, black pants with a black belt, and black shoes. When he's being an art teacher, he wears a gold-colored apron with paint smears and pockets to hold art supplies.
In Alien World, Rippen replaces a Kronad.
In Arabian World, Rippen replaces a bandit.
In Ball World, Rippen replaces a tennis racket.
In Cereal World, Rippen replaces a cereal mascot named Wrong-Way Wally.
In Clown World, Rippen replaces the criminal clown Farpling.
In Demon World, because a sick Rippen takes the day off and Larry substitutes as the part-time villain, Rippen replaces a skeleton minion.
Only having a skeleton for a body, he is very fragile, getting crushed when Larry, in his muscular overlord form, hugs him.
In Dinosaur Cowboy World, Rippen replaces a bandit.
In Fairy World, Rippen replace Collatertal Damage.
In Galaxy World, Rippen replaces a person with a metal suit.
In Giant Monster World, Rippen replaces a general of Island City.
In Knight World, Rippen replaces a goblin leader.
In Musical Fairytale World, Rippen replaces a sorceress.
As a sorceress, Rippen possesses magical powers, being able to transform trees into monsters.
Rippen finds it cool being a lady, commenting on how he likes his horns and lipstick, though he is not impressed with his dress and mascara.
At the North Pole, Rippen replaces a gingerbread man.
In Ocean World, Rippen replaces the leader of the Octopus people.
In this form, he can swim underwater and breathe out of water.
In Old English World, Rippen replaces Crossbow, a bandit.
His left hand is replaced with a mini crossbow, which he can use to shoot arrows.
In Outer Space Court World, Rippen replaces an alien general named Ugthar the Ugly.
In Plush Toy World, Rippen replaces a giant baby.
With his size, Rippen is strong, easily able to grab a plane in mid-flight and beat the stuffing out of Mayor Pink Panda. Unfortunately, this doesn't prevent him from immediately being pacified after he is given a hug and a pacifier. As a baby, Rippen can't speak, but he still thinks fluently. But in The Chinchilla (episode)
In Pirate World, Rippen replace Wood Beard.
In Space World, Rippen replaces an alien.
In Superhero World, Rippen replaces a super-villain with a robot suit.
The suit has multiple arms and lasers. It also has a chest compartment that stores Larry, who in this universe is a human parasite. Rippen can use Larry's ability to steal super powers, giving Rippen powers to choose from and use, like super strength, super speed, growth, electricity manipulation, etc. However, if Larry is detached, Rippen looses the powers.
In Temple World, Rippen replaces an adventurer.
In Zombie World, Rippen replaces the owner the of Brainzburgerz restaurant chain. At the end, Rippen becomes a zombie after Zombie Larry forces a burger into his mouth.