The Avengers: Earth's Mightiest Heroes

As 75 of the world's most dangerous super-villains are mysteriously freed from the Vault, the Cube, the Big House, and the Raft, four of Earth's mightiest heroes assemble a crime-fighting alliance called the Avengers. The Avengers team is composed of Iron Man (Tony Stark) as de facto team leader, Ant-Man/Giant-Man (Hank Pym), the Hulk (Bruce Banner), Thor, and the Wasp (Janet Van Dyne).[4] Captain America (Steve Rogers) joins the team later after being found frozen in ice while the team is looking for Hulk. Future members of team for season one include Black Panther (T'Challa) and Hawkeye (Clint Barton). In the season finale, it is revealed that Thor's stepbrother Loki was responsible for the breakouts so that Amora the Enchantress and Skurge the Executioner could build his Masters of Evil to defeat Thor.

Season two uses cold openings and remixes the opening theme song "Fight As One", replacing the original singing vocals with that of Nick Fury, voiced by Alex Désert, introducing the show's concept and main characters.

Season two depicts the Avengers as they track down the remaining members of the Masters of Evil and end up facing the invasions of the Skrulls in the first half of the season and the Kree in the second half. The Avengers are unaware that Captain America had been replaced at the end of season one by a Skrull operative as part of their systematic infiltration of Earth. The season also alludes to a developing storyline that Surtur, now free of his imprisonment in Muspelheim, is slowly gathering his strength to oppose the Avengers as a prelude to Ragnarök. Ms. Marvel joins the team, followed by the Vision. Many other characters from the Marvel Comics universe make appearances, such as Spider-Man, Wolverine, Scott Lang (the second Ant-Man) and his daughter Cassandra, Heroes for Hire, Doctor Doom, Crossfire, Thaddeus E. "Thunderbolt" Ross (in both his human and "Red Hulk" forms), the Guardians of the Galaxy (composed of Star-Lord, Rocket Raccoon, Groot, Quasar and Adam Warlock), Quake, Beta Ray Bill, the Falcon, the Winter Soldier, and Galactus and his heralds. Series producers Joshua Fine and Christopher Yost revealed that certain returning characters would adopt their Ultimate Universe counterpart costumes for the second season, such as Nick Fury appearing more like Ultimate Nick Fury with a shaven head and goatee, and the Skrull operative posing as Captain America wearing the Ultimate Captain America costume and wielding an energy shield.[5] The second-season premiere, titled "The Private War of Dr. Doom" (featuring Dr. Doom and the Fantastic Four), was shown to audiences at both the 2011 San Diego and New York Comic Cons, as well as the 2012 WonderCon in Anaheim.[6] It premiered with the two-part Ultimate Spider-Man pilot on April 1, 2012.[7]

• Brian Bloom[8] – Captain America
• Chris Cox – Hawkeye, Crimson Dynamo, Fandral, Rattler
• Jennifer Hale – Ms. Marvel, Corina Korvac
• Peter Jessop – Vision
• Phil LaMarr[9] – J.A.R.V.I.S., Wonder Man
• Eric Loomis[10] – Iron Man
• James C. Mathis III[11] – Black Panther, Bulldozer, Cobra
• Colleen O'Shaughnessey[9] – Wasp, Cassandra Lang, Vapor
• Fred Tatasciore[9] – Hulk, Graviton, Griffin, Kalum Lo, Mandrill, Red Hulk, Thing, Volstagg, Yon-Rogg
• Rick D. Wasserman[9] – Thor, Absorbing Man, Surtur
• Wally Wingert[9] – Ant-Man/Giant-Man/Yellowjacket, MODOK

The Avengers: Earth's Mightiest Heroes was not renewed for a third season and was succeeded by a new Avengers show called Avengers Assemble in 2013.[20] On Saturday, July 14, 2012, at the 2012 Marvel Television Presents panel at San Diego Comic-Con, Jeph Loeb, Head of Marvel Television, said of the relationship between the two shows:

We're not in any way saying Earth's Mightiest Heroes never happened. You will see an epic conclusion. And then you'll say, 'Oh, what's next?'[21]

The only voice actors to reprise their roles for Avengers Assemble are Fred Tatasciore[22] and James Matthis III[23] as the Hulk and Black Panther, respectively. Additionally, Drake Bell returned to voice Spider-Man for guest appearances, while the other members of the team share their voices with their counterparts in the separate Ultimate Spider-Man series.[22]

The Avengers: Earth's Mightiest Heroes comic book series, written by Christopher Yost, and artwork by Scott Wegener, Christopher Jones and Patrick Scherberger was published to accompany the series. It was a four-issue limited series.[24] An ongoing comic book series titled The Avengers: Earth's Mightiest Heroes Adventures debuted in April 2012, alongside the Ultimate Spider-Man Adventures series. Christopher Yost returned as the main writer, with Adam Dekraker serving as the comic's creative team, while Nuno Plati provided artwork.[25]