The Ben 10 Humungasaur is a 12 foot tall alien monster that can grow up to 60 feet tall at will. The Boy's Classic Muscle Ben 10 Humungasaurus Costume features a green jumpsuit with broad padded muscles in the arms, shoulders and torso. It comes with a matching Humungasaurus Character mask. Its the perfect costume for young Ben 10 enthusiasts. The hand makeup shown in the image is sold separately. He has a humanoid body and bears the Omnitrix symbol on his chest. When he grows taller, he sprouts spikes making him even more formidable. He is the third alien to appear in Alien Force.