Ro-Man
Ro-Man was an extraterrestrial who tried to invade Earth once and was repelled by a gathering of superheroes, the Space Patrol, and Stardust the Super-Wizard.
Appearing to be a gorilla in a helmet, Ro-Man was actually an energy being who merely possessed the simian body (actually belonging to an innocent alien named Hezton). The helmet shielded Ro-Man from electromagnetic interference.
When he returned to Earth seeking revenge for his defeat, he was instead defeated himself. When he attempted to abandon one host body for a more combat capable one, the superhero Dynamo deflected him instead to his own shielded helmet, trapping him. (COMIC: Ruthless Ro-Man)
Behind the scenes
Ro-Man originated as the titular antagonist of the infamous 1953 low-budget B-movie Robot Monster. Although he is frequently believed to be in the public domain, this is not actually the case, with his usage in Kaza's Mate, Gwenna being unauthorised.