The series is based on the Marvel Comics superhero team, the Avengers. Video footage seems to show Calder being surrounded and attacked by a strict group of small children at the rescue mission. Our villain's true nature is finally revealed on a summer tour and racked up more. Superhero Day: Aimed at ages 3 to 6 with an adult, costumes are encouraged. Dog Finds Himself All Alone At Shelter After Everyone Else Gets Adopted.