This is an episode list for The Avengers: Earth's Mightiest Heroes. The series is based on the Marvel Comics superhero team, the Avengers. A 20 part micro-series focusing on each hero's backstory debuted on September 22, 2010 on Disney XD. The first season premiered on Disney XD in the United States on October 20, 2010. The second season premiered on April 1, 2012.