Dumptruck is another member of the air pirates, who's often seen in the company of Mad Dog. He's a very tall and muscular guy, though as expected he's also a dumb kind.
Don karnage uses him when Mad dog is not available or when he needs some brute force. He's also seen commanding the air pirates in one episode, due to the absence of "Captain Karnage" who named him temporarily for that leader position.
Ep. 48 Jumping the Guns
His muscular arms shown in a disguise