The main characters in the American cartoon "The Avengers" were all characters from Marvel Comics. 1 Iron Man (Tony Stark)-From the Marvel Comics 'Iron Man series, he was a genius inventor and billionaire, and one of the leaders of the Avengers. 2. Captain America (Steve Roger)-From the Marvel Comics 'Captain America series, he was a righteous and upright warrior and another leader of the Avengers. 3. Thor-From the Marvel Comics series, Thor is a powerful Thunder God with the power of lightning and a member of the Avengers. 4 Hulk (Hulk)-From the Marvel Comics series Hulk is an unusually strong villain and one of the enemies of the Avengers. 5 Black Widow-From the Marvel Comics 'Black Widow series, an agent with super combat ability and spy skills is also a member of the Avengers.