The Avengers, Earth's Mightiest Heroes against the legendary King of the Monsters, Godzilla.
The movie begins with a flashback, going back to the year 1999 as a team of S.H.I.E.L.D. agents led by Coulson, fighting against a giant radioactive dinosaur called Godzilla to Antarctica after the creature attack Tokyo as they manage to cause an avalanche, trapping Godzilla in ice and placing him in hibernation. As the Helicarrier arrives, Coulson contains Nick Fury, confirming that Godzilla has been defeated.
- Doctor Demonicus
- Godzilla -
- Centipor -
- Batragon -
- Mick Wingert as Tony Stark / Iron Man, the benefactor the Avengers, who is a self-described genius, billionaire, playboy, and philanthropist with electromechanical suits of armor of his own making.
- Roger Craig Smith as Steve Rogers / Captain America, the leader of the Avengers, and a World War II veteran who was enhanced to the peak of human physicality by an experimental serum and frozen in suspended animation before waking up in the modern world.
- Scott Porter as Peter Parker / Spider-Man, an Avenger and a 23-year-old brilliant physics graduate at Columbia University and a prodigy in Pym Industries who developed spider-like abilities from a genetically-modified spider and uses them to take up the persona of a spider-based vigilante protecting New York City from its criminal underworld.
- Jennifer Hale as Carol Danvers / Captain Marvel, an Avenger and a U.S. Air Force pilot whose DNA is fused with that of Kree warrior Mar-Vell's during an accident, which imbues her with the powers of superhuman strength, energy projection and flight.
- Kathreen Khavari as Kamala Khan / Ms. Marvel, the Avengers' protegée and a 13-year-old young Inhuman girl who developed the abilities of Size/Shape shifting and Healing factor after exposing herself to the Terrigen Mist on Earth and she uses them to take up the persona of her childhood idol Carol Danvers' former alter-ego and to protect her homestead from its criminal underworld.
- Fred Tatasciore and Kirk Thornton as Bruce Banner / Hulk, an Avenger and a genius scientist who, because of exposure to gamma radiation, transforms into a monster when enraged or agitated.
- Travis Willingham as Thor, an Avenger and the crown prince of Asgard, based on the Norse mythological deity of the same name.
- Laura Bailey as Natasha Romanoff / Black Widow, an Avenger, a highly trained spy, and a former agent of S.H.I.E.L.D.
- Troy Baker as Clint Barton / Hawkeye, an Avenger and master archer who previously worked as an agent for S.H.I.E.L.D..
- TBA as Douglas Birely / Doctor Demonicus - a supervillain possesed advanced knowledge of genectic engineering.
- Godzilla has the appearance of the KiryuGoji suit.