Boomerang is a Marvel Comics character.  He is typically grouped as a Spider-Man foe, but began his career fighting the Hulk.  He’s really Fred Myers, former baseball player famed for his pitching arm.  He was thrown out of the major leagues due to accepting bribes.  So, he turned to a life of crime, as one does.  He was armed with a variety of weaponized boomerangs.  He has bounced around a lot, maintaining a career as a c-list villain.  He’s been featured as a prominent member of the Sinister Six, a group of Spider-Man villains, and the Thunderbolts, a group of former villains.  Recently, he formed his own version of the Sinister Six, which was quickly defeated by an Otto Octavius-controlled Spider-Man.