The Adventures of the American Rabbit (1986)

This animated film features Rob Rabbit (Barry Gordon), who's not your typical bunny. After saving his friends at a picnic, Rob realizes he can turn into a superhero, decked out in a star-spangled flag and roller skates. He moves to the city and gets a job at a piano bar, where the owners are being hassled by jackals. Rob tries fighting them by raising money to start a union so that they don't have to pay for protection. But when the jackals refuse to lay off, Rob must break out his superpowers.