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 debuted in the main 616 universe in Thor (2020) issue 18.
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 Talk: This series establishes that, in the Marvel Universe, all animals can talk to each other. As frogs, the Avengers can understand the Pet Avengers, but lose that ability upon returning to human form.
- 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...Thor: [facepalm] Not again.
- 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.
- Forced Transformation: 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.
- Found Family: Avengers vs. Pet Avengers is the first time Ms. Lion refers to them all as a family together, now living under one roof.
- The Heart: Ms. Lion has no powers or abilities, but defuses a few situations by his own ability to understand and care for others' needs. For this reason, he stays.
- Huggy, Huggy Hippos: The hippo who escapes the zoo in Lockjaw And The Pet Avengers Unleashed is sweet enough to not lift a foot against the Avengers trying to stop her, although its primarily because she's a living tank who can't be stopped by any of their efforts. She even warns Ms. Lion when it seems like she might hurt him, and agrees to return to her enclosure when she's reminded of her son inside.
- 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.
- Non-Indicative Name: Ms. Lion is male. He's also a dog.
- Predator-Prey Friendship: Two members of the team, Hairball and Redwing, are natural enemies. Hairball even offers to join the team so long as he gets to eat Redwing, which is promptly nyxed, and the two are shown to get along afterwards.
- Swallowed Whole:
- While visiting underwater in Lockjaw and the Pet Avengers, the crew accidentally wakes up Giganto and are devoured in one gulp by him. Inside his gut, they discover two of the Infinity Stones they were searching for, and use Lockjaw's powers to teleport away.
- Then again in Avengers vs Pet Avengers, Fin Fang Foom's dragon army swallow up every member, but thanks to Lockjaw's aforementioned teleportation, it's a non-issue.
