The Avengers: Earth's Mightiest Heroes!

The Avengers: Earth's Mightiest Heroes aired in October 20, 2010, and ended in March 24, 2013.

Season 1:
As the world's most dangerous super-villains break out of the Vault, the Cube, the Big House, and the Raft, five of Earth's mightiest heroes assemble a crime fighting alliance called the Avengers. The Avengers team includes Iron Man as team leader, Ant-Man, Thor, The Hulk, and The Wasp. Captain America, Black Panther, and Hawkeye have since joined the roster. When it comes to the Season Finale, it was revealed that Thor's brother Loki was responsible for the breakouts and having Enchantress form the Masters of Evil.

Season 2:
Season Two will depict the Avengers as they track down the remaining members of the Masters of Evil and end up getting involved in the upcoming war between the Kree and the Skrull. The Avengers are unaware that Captain America has been replaced by a Skrull. Ms. Marvel, Vision, Falcon, and Mockingbird will join the Avengers. Many other characters from the Marvel Universe such as Doctor Doom, Surtur, Thunderbolt Ross' Red Hulk form, and Guardians of the Galaxy have been confirmed to make appearances. Series producers Joshua Fine and Christopher Yost have revealed that certain returning characters will adapt their Ultimate Universe counterpart costumes, such as Director Fury who returns in Season 2 appearing more like the Ultimate Universe Fury with a shaved head and goatee and the Skrull who replaced Captain America will wear the costume directly adapted from Ultimate Captain America and will use an energy shield.

Season 3:
The Avengers must prove they can deal with Thanos! Due to Thanos murdering, the season will have a darker tone, Captain America wears his Commander America uniform from Steve Rogers: The Erskine Legacy, Ms. Marvel's costume now shows her bare midrift, and she has shorter hair and ever since Iron Man is Born, Lt. Col. Rhodes and the army have been trying to discover who built Ultimo,

The Avengers:

 * Captain America (Brian Bloom) - the new leader of the Avengers in "Code Red" and season 3
 * Tony Stark/Iron Man (Eric Loomis) - leader in seasons 1-2, later second-in-command in season 3, and leader of the Illuminati
 * Hulk (Gabriel Mann/Fred Tatasciore)
 * Hank Pym/Ant-Man/Yellowjacket (Wally Wingert) - became Yellowjacket in "Yellowjacket"
 * Thor (Rick D. Wasserman, Michael Adamthwhite for teenager) -
 * Wasp (Colleen O'Shaughnessey) -
 * T'Challa/Black Panther (James C. Mathis III)
 * Ms. Marvel (Jennifer Hale) -
 * Vision (Peter Jessop) -
 * Spider-Man (Drake Bell, Josh Keaton for Season 3) - appears as a reservist member
 * Falcon (Lance Reddick)
 * Jennifer Walters/She-Hulk (Alyson Stoner)
 * Pietro Maximoff/Quicksilver (Mark Hildreth)
 * Wanda Maximoff/Scarlet Witch (Kate Higgins)

West Coast Avengers:

 * Clint Barton/Hawkeye (Chris Cox)
 * Mockingbird (Elizabeth Daily)
 * Rhodey Jones/War Machine (Bumper Robinson)
 * Simon Williams/Wonder Man (Phil LaMarr)
 * Greer Grant/ Hellcat/ Tigra (Ashley Beill)
 * Marc Spector/Moon Knight (Kirk Thornton)

Inhumans:

 * Black Bolt
 * Medusa (Grey DeLisle)
 * Karnak (Steven Blum)
 * Gorgon (Greg Eagles)
 * Triton (Richard Green)
 * Crystal (Kim Mai Guest)
 * Maximus the Mad (Troy Baker)
 * Lockjaw (Dee Bradley Baker)
 * Sentry 219 (Mark Hamill)

Fantastic Four:

 * Mr. Fantastic (Dee Bradley Baker)
 * Invisible Woman (Erin Torpey)
 * Human Torch (David Kaufman)
 * Thing (Clancy Brown)

X-Men:

 * Professor Charles Xavier (Jim Ward)
 * Cyclops (Nolan North)
 * Jean Grey (Jennifer Hale)
 * Wolverine (Steve Blum)
 * Colossus (Phil Morris)
 * Storm (Susan Dalian)
 * Thunderbird (Michael Horse)
 * Banshee (Nick Chunlind)
 * Kitty Pryde (Tara Strong)
 * Doctor Strange (Xander Berkley)
 * Namor (James Patrick Stewart)

S.H.I.E.L.D.:

 * Nick Fury (Alex Desert)
 * Black Widow (Vanessa Marshall)
 * Quake (Lacey Chalbert)
 * Maria Hill (Kari Wuhrer)
 * Clay Quartermain (Troy Baker)
 * Jimmy Woo (Nolan North)
 * Jasper Sitwell (Tom Kane)
 * Phil Coulson (Clark Gregg)

Allies:

 * Pepper Potts (Dawn Oliveri) -
 * Balder (Nolan North)
 * Captain Mar-Vell (Roger Craig Smith)
 * Sword:
 * Abigail Brand (Mary Elizabeth McGlynn)
 * Sydren (Troy Baker)
 * Henry Gyrich (Jim Ward)
 * Luke Cage (Christopher B. Duncan) 
 * Iron Fist (Loren Lester)
 * Scott Lang/Ant-Man (Crispin Freeman)
 * Cassandra Lang (Colleen O'Shaughnessey)
 * Guardians of the Galaxy:
 * Star-Lord (Steve Downes)
 * Adam Warlock (Kirk Thornton)
 * Groot (Troy Baker)
 * Rocket Raccoon (Greg Ellis)
 * Quasar (Moira Quirk)
 * Carina Korvac (Jennifer Hale)
 * Beta Ray Bill (Steven Blum)
 * Lady Sif (Nika Futterman, Tara Strong for teenager)
 * Jane Foster (Kari Wahlgren)
 * Winter Soldier (Jon Curry)
 * Tyrone "Ty" Johnson/Cloak (Khary Payton)
 * Doc Samson (Cam Clarke)
 * Odin (Corey Burton ) - retakes his place after Kurse Posed as him.
 * Silver Surfer (Yuri Lowenthal)
 * Mary Jane Watson (Alyssa Milano)
 * 3-D Man (Kim Struss)
 * Machine Man (Alan Tudyk)
 * Bill Foster/Giant-Man II (Chi McBride)
 * Uatu the Watcher (Stan Lee)
 * Sasquatch
 * Omega the Unknown (Don Leslie)
 * Rom the Space Warrior (Daniel Riordan)
 * Morbius (Peter Stormare)
 * Crystar (Dominic Scott Kay)
 * Human Fly (Will Ryan) - a fellow circus performer of Hawkeye's
 * Uatu the Watcher (Alan Tudyk) - makes a major appearance in the 3-part series finale, He helps Thor and Jane reignite their relationship.
 * The Avengers of the House of M:
 * Luke Cage (Christopher B. Duncan) - leader
 * Hawkeye (Chris Cox)
 * Mockingbird (Elizabeth Daily)
 * Cloak (Khary Payton)
 * Iron Fist (Loren Lester)
 * Moon Knight (Kirk Thornton)
 * Felicia Hardy/Black Cat (Juliet Landau)
 * Angela Del Toro/White Tiger (Andrea Baker)
 * Misty Knight (T'Keyah Keymah)
 * Tigra (Ashley Beill)
 * Lotus Shinchuko (Kim Mai Guest)
 * The Dragons (House of M):
 * Shang-Chi (Vincent Tong)
 * Colleen Wing (Maggie Q)
 * Swordsman (Jeffrey Tambor)
 * Mantis (Grey DeLisle) - Swordsman's wife
 * Zaran (Robert Patrick)
 * Machete (Jim Meskimen)

Season 1:

 * Loki (Graham McTavish, Rick Gomez for teenager) - the main antagonist, was the cause of the Breakouts, and had the Enchantress form the Masters of Evil
 * Baron Strucker (Jim Ward) - One of the key villains of Season 1
 * Ultron (Tom Kane) - One of the key villains of Season 1
 * M.O.D.O.C. (Wally Wingert) - One of the key villains of Season 1
 * Kang the Conqueror (Jonathan Adams) - One of the key villains of Season 1
 * Leader (Jeffrey Combs) - One of the key villains of Season 1
 * The Masters of Evil:
 * Baron Zemo (Robin Atkin Downes) - revealed to be the son of Baron Zemo, and realizes the true potential and heart of Captain America and asks for a truce!
 * Enchantress (Kari Wahlgren)
 * Executioner (John DiMaggio)
 * Crimson Dynamo (Chris Cox)
 * Abombination (Robin Atkin Downes)
 * Wonder Man (Phil Lamaar)
 * Chemistro (Nolan North)
 * Living Laser (Nolan North)
 * Grey Gargoyle (Troy Baker)
 * Arnim Zola (Grant Moninger)

Season 2:

 * Kang the Conqueror (Jonathan Freeman) - he is the main antagonist of season 2, he escapes to stop the Avengers once again before they end up causing the destruction of his timeline by letting Black Panther live during the destruction of Earth's Sun by the Kree, after he was defeated by the New Avengers in "New Avengers", Spider-Man makes him go through the portal and is seen being chased by a Carnotaurus.
 * Red Skull (Steve Blum) - revealed to be alive, disguised as Dell Rusk, the head of the US Dept. of Security, to finally have his revenge on Captain America, defeated and was locked up in Prison 42.
 * Thaddeus Ross/Red Hulk (Keith Ferguson/Fred Tatasciore) - Ross is transformed into the Red Hulk by the Winter Soldier on orders from Red Hulk in order to finally have his revenge on Hulk.
 * A.I.M.:
 * Scientist Supreme (Nolan North)
 * Dr. Lyle Getz (Kyle Hebert)
 * Surtur (Rick D. Wasserman) - he has Enchantress plant the Seeds of Destruction as Ragnarok starts to conquer midgard. He remains at large
 * Enchantress (Kari Wahlgren) - trapped under Surtur's control, the Enchantress serves as the Dragon to the Fire Giant for Seasons 2
 * Doctor Doom (Lex Lang) - he remains at large
 * Ultron-7 (Tom Kane) - having rebuilt himself yet again following his destruction at the hands of Hank Pym.
 * Skrulls:
 * Veranke (Elizabeth Daily) - Queen of the Skrulls, and one of the main antagonists from Season 2.
 * Criti Noll (Brian Bloom) - The Captain America Imposter, and Veranke's second-in-command of the Skrull Fleet.
 * Super Skrull (Kyle Hebert) -Veranke's third-in-command of the Skrull Empire, and leader of the Super Skrull army.
 * Kree:
 * Kalum Lo (Fred Tatasciore)
 * Ronan the Accuser (Keith Szarabajka)
 * Sentry-459
 * Supreme Intelligence (David Kaye season 2, Dee Bradley Baker season 3)
 * Yon-Rogg (Fred Tatasciore)

Season 3:

 * Thanos (Michael Ironside) - the main antagonist, gone on a quest to search for the Infinity Gems. When he defeats his enemies, he snaps their necks, he also uses his powers to drain the victims's souls from their bodies and absorbs them into his being in order to amplify his powers. His victims will include the Guardians of the Galaxy, Supreme Intelligence, Veranke, Michael Korvac, and Yon-Rogg. His goals are to kill everyone and become a god, his hobby include killing and playing god
 * Magneto (Ron Perlman) - the Mutant leader who wants to destroy the Avengers and destroy the freedom of Human kind.
 * Doctor Doom (Mark Hamill) - ever since he was roomates with Reed Richards, he plans to ressurect his mother, Cynthia von Doom from the Realm of Mephisto
 * Surtur (Rick D. Wasserman) - has plans to start Ragnarok
 * Mandarin (James Hong) - he doesn't believe in heroes, as he is like his Iron Man 3 counterpart, with the phrase, "Heroes, there is no such thing!", "Some people call me a terrorist, I consider myself a teacher!"
 * Ultimo  (Daran Norris)
 * A.I.M.:
 * M.O.D.O.C. (Wally Wingert) - in league with the Mandarin
 * Aldrich Killian (Nolan North) - the scientist supreme, which is why he believes Pepper to remember him, he used to ask her out all the time
 * Fin Fang Foom - the dragon the Mandarin plans to summon to start the Makulan Invasion
 * Masters of Evil III:
 * Baron Zemo (Robin Atkin Downes)
 * Absorbing Man (Rick D. Wasserman)
 * Marcus Daniels/Blackout (Jim Meskimen)
 * Tanya Seely/Black Mamba (Jennifer Martin)
 * Paul Norbert Ebersol/Fixer (Phil Morris)
 * Erik Josten/Goliath (Khary Payton)
 * Grey Gargoyle (Troy Baker)
 * Calvin Zobi/Mr. Hyde (Dwight Schultz)
 * Moonstone (Jodi Benson)
 * Screaming Mimi (Maggie Q)
 * Tiger Shark (James Horan)
 * Titania (Kath Soucie)
 * Whirlwind (Troy Baker)
 * Wrecking Crew:
 * Wrecker (JB Blanc)
 * Bulldozer (James C. Mathis III)
 * Piledriver (Nolan North)
 * Thunderball (Gary Anthony Williams)
 * Rita DeMara/Yellowjacket II (Jessica DiCicco)
 * Kang the Conqueror (Jonathan Freeman) - returns and learns Thanos has the Infinity Gauntlet and makes a deal to rid of Captain America being put on ice
 * Mistress Death (April Stewart) - Thanos stole the Infinity Gauntlet in order to bring death and destruction to the universe

Other villains

 * Absorbing Man (Rick D. Wasserman)
 * Annihilus - revealed to have made a deal with Kang to cause the attack on 42
 * Armadillo
 * Aldrich Killian - makes a cameo in Iron Man's past.
 * Bi-Beast
 * Blizzard (Troy Baker) - killed by the Annihilation Wave in "Assault on 42"
 * Buck Chisholm/Trickshot (Jim Meskimen) - Clint's mentor in archery
 * Circus of Crime:
 * Bruto the Strongman (Richard McGonagle)
 * Cannonball (J.B. Blanc)
 * Clown (Charlie Adler)
 * Fire-Eater (Ogie Banks)
 * Flying Gambonnos (Jeff Bennett and Maurice LaMarche)
 * Livewire (Cindy Robinson)
 * Princesss Python (Tara Strong)
 * Ringmaster (Corey Burton)
 * Crossbones (???) - works with Red Skull, Baron Strucker and Grim Reaper in "The Parents of Peter Parker"
 * Crossfire (Neil Ross)
 * Death-Throws:
 * Charles Last/Ringleader (Dwight Schultz)
 * Wendy Conrad/Bombshell (Cindy Robinson)
 * Nicholas Grossman/Knicknack (Grant Moninger)
 * Alvin Healy/Tinpin (Don Leslie)
 * Elton Healey/Oddball (Sam Riegel - using Arkana from Yu-Gi-Oh's tone)
 * Glenn Talbot (Troy Baker)
 * Graviton (Fred Tatasciore)
 * Norman Osborn/Green Goblin (Mark Rolston for Norman Osborn, Kevin Michael Richardson for Green Goblin)
 * Griffin (Fred Tatasciore)
 * Heralds of Galactus
 * Air-Walker
 * Firelord
 * Stardust
 * Terrax (Kevin Grevioux)
 * Parker Robbins/Hood (Jim Meskimen)
 * The Inner Circle Club:
 * Sebastian Shaw (Graham McTavish)
 * Emma Frost (Kari Wahlgren) - appeared in Illuminati helping Norman Osborn build a Cabal for a future organization known as the Lethal Legion, but failed as she and the rest of the Inner Circle escaped
 * Harry Leland (J.B. Blanc)
 * Donald Pierce (Tim Conway)
 * Selene (April Stewart)
 * Algrim the Kurse (Ron Halder/Clancy Brown) - posed as Odin in Season One, and 2 and released Surtur, was destroyed by Loki and Thor
 * Klaw (Mark Hamill)
 * Lucia Von Bardas (Kirsten Potter)
 * Mad Thinker (Danny Mann)
 * Madman (Dee Bradley Baker)
 * Malekith (Quinton Flynn)
 * Mandrill (Fred Tatasciore)
 * Michael Korvac (Troy Baker)
 * Purple Man (Brent Spiner)
 * Professor Thornton (Tom Kane)
 * Ravonna (Cindy Robinson)
 * Red Ghost
 * Serpent Society:
 * King Cobra (James C. Mathis III)
 * Anaconda (Vanessa Marshall)
 * Bushmaster (Phill LaMarr)
 * Constrictor (Cam Clarke in Season 1, Troy Baker in Season 2)
 * Death Adder (Dee Bradley Baker)
 * Rattler (Chris Cox)
 * Madame Viper (Vanessa Marshall)
 * Sinister Six:
 * Doctor Octopus (Corey Burton)
 * Vulture (Corey Burton)
 * Electro (Crispin Glover) - kills the Jamie Foxx Skrull!
 * Sandman (Wade Williams)
 * Mysterio (Kevin Michael Richardson)
 * Kraven the Hunter (Hector Elizondo) - is offered the role in the Cabal.
 * Swordsman (Jeffrey Tambor - using Crazy Quilt's tone)
 * Technovore (Dwight Schultz)
 * U-Foes:
 * Vector (Cam Clarke)
 * Ironclad (Kevin Michael Richardson)
 * Vapor (Colleen O'Shaughnessey)
 * X-Ray (Dee Bradley Baker)
 * Ultimo (Peter Stormare)
 * Whiplash
 * Wrecking Crew:
 * Wrecker (J.B. Blanc)
 * Bulldozer (James C. Mathis III)
 * Piledriver (Nolan North)
 * Thunderball (Gary Anthony Williams)
 * Zzzax