Watch The Avengers: Earth's Mightiest Heroes Season HD Full Free on solarmovie.do. Watch The Avengers: Earth's Mightiest Heroes tv series online free. After 74 villains break out of prison, Marvel's most powerful superheroes team up to capture all of ...After 74 villains break out of prison, Marvel's most powerful superheroes team up to capture all of them, and also to defend the Earth from widespread threats.