The characters in Avenger Penguins.
The leader of the Avenger Penguins.
- Deadpan Snarker: He frequently makes remarks about Rocky's stupidity.
- The Leader: He's the leader of the team.
The largest of the Avenger Penguins and not very bright.
- The Big Guy: He's the largest and strongest of the Avenger Penguins.
- Dumb Muscle: He's the strongest of the group and not very bright.
- Embarrassing First Name: "Mommy's Boy" reveals that his first name is actually Rockville. He's not very proud of it.
- Interspecies Romance: He's a penguin and he's in love with the human Dolores Divine.
- Simpleton Voice: He talks with the typical deep, goofy voice used to indicate idiocy.
The third Avenger Penguin.
- Eye-Obscuring Hat: His helmet usually covers up his eyes.
- The Unintelligible: He only talks in gibberish.
A female penguin allied with the Avenger Penguins who works at the Slush City malt shop.
- Non-Mammal Mammaries: She's a female penguin with breasts.
- Pink Means Feminine: She wears pink clothes.
The Doc from Saskatoon
One of the regular patrons at Slush City.
- Companion Cube: He hangs around with a cactus that he regards as his best friend.
Another patron of Slush City.
- Non-Human Head: He has a television set for a head, though a normal head is displayed on the screen.
The Badly Drawn Brothers
A pair of brothers who live up to their name by being unfinished doodles.
- Stylistic Suck: They're deliberately drawn poorly with unfinished detail.
- Those Two Guys: They're always seen together.
The muscle of the Stink Brothers.
- The Brute: He's a strong thug.
- Evil Counterpart: He's an evil equivalent to Rocky.
The leader of the Stink Brothers.
- Evil Counterpart: He's the villainous equivalent of Marlon.
The third member of the Stink Brothers.
- Evil Counterpart: He's an evil version of Bluey.
Dr. Caractacus P. Doom
The main foe of the Avenger Penguins.
- Bald of Evil: He has no hair and is a villain.
- Big Bad: He's the main antagonist of the series.
- Evil Is Hammy: He's a villain and very melodramatic.
- Fat Bastard: He's evil and obese.
- They Called Me Mad!: He often rambles on how people have called him mad.
- Villain Song: In the Musical Episode "Rock 'n Roll Penguins", he sings "Caractacus P. Doom Will Rule the World".
- We Will Meet Again: The series' premiere episode "The President Is a Fish" has him vowing to get even with the Avenger Penguins as his lair crumbles.
Caractacus P. Doom's right-hand man.
- Bald of Evil: Like his boss, he's a bad guy who lacks hair.
- The Dragon: He's second-in-command to Caractacus P. Doom.
- The Igor: He's a short and deformed assistant.
An actress who's not very bright.
- Alliterative Name: Her first name and last name both begin with D.
- Brainless Beauty: She's gorgeous, but just as dim as Rocky.
- Dumb Blonde: She has blonde hair and is a complete ditz.
- Interspecies Romance: She's a human in love with the penguin Rocky.
Miss Leatherclad Fullarain
A female secret agent Rocky encounters in "Fishfinger".
- Catchphrase: Her catch phrase is a rapid-fire Big "NEVER!".
- Red Is Heroic: She wears a red uniform.
The Avenger Penguins' mechanic.
- The Pig-Pen: He tends to be messy and untidy.
The Sweetheart Fairy Angel
- Hair of Gold, Heart of Gold: She has blonde hair and is a very kind fairy.