There's a reason why Marvel fans constantly demand that The Avengers: Earth's Mightiest Heroes return to television a decade after its first aired. The show was Marvel's equivalent to the DCAU's Justice League: a sprawling multi-character epic that reinvented classic and obscure heroes while telling complex stories pulled from all corners of the Marvel universe. It featured great action, strong relationships, humor that was neither forced or juvenile and a fantastic theme song, making for one of the best superhero cartoons ever made. Unfortunately, it also lasted only two seasons on Disney XD before getting canceled, joining the likes of Spectacular Spider-Man, Green Lantern: The Animated Series and Thundercats in a lineup of beloved cartoons canceled far too early by networks before they could embrace their full potential.
With no major live-action blueprints beyond Robert Downey Jr.'s two Iron Man films and The Incredible Hulk, showrunners Joshua Fine and Christopher Yost had to develop their entire B-list cast of superheroes from scratch. They achieved this through a series of micro-episodes which helped establish the personalities of Iron Man, Thor, Hulk, Ant-Man and Wasp, as well as future Avengers Captain America, Black Panther and Hawkeye. For a lot of fans getting into Marvel before the Marvel Cinematic Universe became a pop-culture juggernaut, this was likely their first introduction to its characters.
It helps that the two-part storyline which united the Avengers, titled "Breakout," is just as compelling as its MCU counterpart. Heavily resembling the inciting incident of Brian Michael Bendis' New Avengers run, when a mysterious coordinated attack disables four major super-prisons -- The Raft, the Vault, the Big House and the Cube -- Ant-Man, Wasp, Iron Man and Thor arrive to contain the prisoners. This leads to the four heroes working together to defeat Graviton, whose powers threaten to level all of New York, thanks in part to the Hulk's late assistance. Having escaped the Cube, Hulk reluctantly accepts Bruce Banner's desire to help them in hopes of changing public opinion about him being a monster, on the condition that Hulk receives full control of their body. Realizing the good they can do together, the Avengers are formed to help capture the remaining 74 supervillains at large and protect humanity from future threats.
What stands out about Earth's Mightiest Heroes is its unabashed Marvel-ness. Not constrained by any licensed movie framework, the show had total freedom to adapt whatever it wanted, ranging from power struggles between S.H.I.E.L.D., HYDRA and AIM to lesser-known heroes and villains like Mockingbird, Wonder Man, Amora the Enchantress and Kang the Conqueror. Each episode felt interconnected, always setting up some new relationship or plotline that eventually payed off in adaptations of classic Marvel storylines. Something as simple as Captain America getting unfrozen, for example, would not only tie into the motives of former WWII adversary Baron Zemo but also Kang's goal to stop a future cataclysm linked to the Captain's time displacement.
As for the Avengers themselves, each character felt likable, multidimensional and well-written. Equal attention was given to big names like Captain America, Thor and an MCU-inspired Iron Man as unknown commodities like Wasp, Black Panther and Hawkeye, all of whom became fan-favorites long before their live-action debuts. In traditional Marvel fashion the heroes were incredibly flawed, regularly butting heads at Avengers Mansion and even suffering major defeats against adversaries, but never did the show regress their behaviors for the sake of rehashing a life lesson about teamwork. The show's voice cast also remains fantastic over a decade later, with some actors like Fred Tatasciore (Hulk) and James C Mathis III (Black Panther) even reprising their roles for future cartoons.
Trying to list the best moments of Earth's Mightiest Heroes' first season could likely amount to saying "everything." However, some standout moments include the "Gamma World" storyline, Hawkeye's search for Black Widow after she framed him as a Hydra double-agent, Mar-Vell's introduction foreshadowing the Kree-Skull war and Kang's invasion of Earth, which in turn lead to the corruption of Hank Pym's robot Ultron. This all built to an epic final battle between the Avengers and Loki -- the mastermind of Season 1's events -- over the fate of the Nine Realms.
By comparison, Season 2 of EMH felt reminiscent of Justice League Unlimited in how it further expanded the character roster. Not only did the Avengers gain new members in Ms. Marvel and Vision, but viewers were introduced to more street-level and cosmic characters like the Fantastic Four, Spider-Man, S.W.O.R.D., the Heroes for Hire, Beta Ray Bill and even the Guardians of the Galaxy. At the same time, however, Earth became a battleground for the Kree-Skrull War, brilliantly adapting Marvel's "Secret Invasion" storyline through the reveal of multiple Skrulls infiltrator, one of whom managed to infiltrate the Avengers. And, in traditional EMH fashion, it also set up plenty of foreshadowing for Season 3, including the threat of Norse demon Surtur and a Super-Human Registration Act that likely would have set up some version of Civil War.
As fans all know, however, the show's cancelation would leave many of these storylines unresolved. Granted, compared to most canceled animated series, Earth's Mightiest Heroes actually got a series finale of sorts, uniting its massive hero roster to stop Galactus from devouring the Earth. Still, that doesn't stop fans from lamenting what could have been, especially with its replacement series Avengers Assemble always feeling constrained by a need to mimic and market the MCU's iconography to younger audiences.
However, despite its short run, The Avengers: Earth's Mightiest Heroes remains a classic for a reason. It successfully adapted the best of both classic Stan Lee/Jack Kirby-era and 2000's contemporary Avengers with almost none of their flaws, introducing audiences to the Marvel world years before it would successfully dominate Hollywood and the public consciousness. Now that 2020 marks the first year without an MCU release since 2009, this is as good a time as any to check out Earth's Mightiest Heroes on Disney+.
Developed by Ciro Nieli, Christopher Yost and Joshua Fine, The Avengers: Earth's Mightiest Heroes is currently available to watch on Disney+.