The team roster, drawn from the pets and animal companions of the Marvel Universe's human superheroes, includes:
- Lockjaw, the dog-like alien pet of The Inhumans
- Hairball, Speedball's pet cat
- Lockheed, Kitty Pryde's Shoulder-Sized Dragon
- Redwing, The Falcon's animal sidekick
- Frog Thor, The Mighty Thor's animal counterpart
- Zabu, Ka-Zar's sabretooth tiger companion
- Ms. Lion, Spider-Man's aunt's lapdog
The Pet Avengers have appeared in:
- Lockjaw and the Pet Avengers (4 issues, 2009): The Pet Avengers are brought together for the first time to aid in a search for the Infinity Gems.
- Pet Avengers Classic (trade paperback, 2009): Collection of pre-Pet Avengers adventures of the various animals.
- Tales of the Pet Avengers (online comic, 2010): Solo adventures.
- Lockjaw and the Pet Avengers Unleashed (4 issues, 2010): The Pet Avengers are reunited to handle a threat facing all the world's mythical creatures.
- Avengers vs. the Pet Avengers (4 issues, 2010-11): The Avengers request the Pet Avengers' aid with Fin Fang Foom and a clutch of dragons, but the two groups come into conflict over the best way to handle the situation.
The Pet Avengers' adventures provide examples of:
- Alternate Universe: Originally they were assumed to be on Earth-616, the regular Marvel Universe. As developments like the Pets of Evil Masters or the Pet Avengers teaming with the regular Avengers made this harder to justify, they were eventually retconned to existing on Earth-97161, where the Intellectual Animal and Animal Talk tropes appear to be a fact of life.
- Amplified Animal Aptitude: Several of the animals in comparison to their previous depiction in human-centric stories. May be justified by their exposure to the Infinity Gems in the first mini.
- Animal Superheroes
- Baleful Polymorph: Avengers vs. Pet Avengers is kicked off with Thor summoning the Pet Avengers because Fin Fang Foom turned him, Captain America, and Iron Man into frogs.
- The Cameo: Barack Obama's dog Bo lends a paw in the first mini.
- Canon Immigrant: Ms. Lion, who had previously only appeared in the Spider-Man and His Amazing Friends animated series.
- Cats Are Mean: Hairball has shades of this, given his tendency to suggest "losing" Ms. Lion at the most deadly places (in the jungle of the Savage Land, under the sea).
- Cats Are Snarkers: Hairball, with Ms. Lion as his most frequent target.
- Continuity Nod: The Avengers' reactions to being turned into frogs by Fin Fang Foom range from freaking out (Iron Man), to taking it totally cool (Captain America), to...
- Covers Always Lie: The final issue of Unleashed has a cover announcing "The Pet Avengers against an incredibly evil beast SO BIG that he won't even fit on the cover!" The Pet Avengers do fight an enormous beast, but "incredibly evil" is not a fair description and it's not nearly the most important thing that happens in the issue.
- The Ditz: Ms. Lion.
- Dogs Are Dumb: Ms. Lion.
- Mixed Animal Species Team: The group consists of various pets of the different superheroes in the Marvel universe. The members include two canines, two felines, a bird, a frog, and a dragon.
- Tagalong Kid / Team Pet: Ms. Lion.
- Vitriolic Best Buds: Hairball and Ms. Lion.