The Avengers: Earth's Mightiest Heroes is an American animated television series by Marvel Animation in cooperation with Film Roman, based on the Marvel Comics superhero team the Avengers. The show debuted both on Disney XD and online in the fall of 2010, starting with a 20-part micro-series. Marvel Entertainment, LLC and Disney XD announced a "new Marvel Universe" programming block, named Marvel Universe, which began broadcasting in April 2012 and included the second season of Earth's Mightiest Heroes! and the animated series Ultimate Spider-Man. The series initially features a team based on the roster for the original Avengers, composed of Iron Man, Giant-Man, Hulk, Thor, and Wasp. The team is later joined by Captain America, Black Panther, and Hawkeye in the first season, and Ms. Marvel and Vision in the second season. In terms of overall tone and style, the series is based principally on the original stories by Stan Lee and Jack Kirby. However, it also tends to utilize material from all eras of the comic's run as well as other sources, such as the Marvel Cinematic Universe. The series was replaced by Marvel's Avengers Assemble, which premiered on July 7, 2013.