Eterno, the Immortal
"...mightier than a million mastodons...more intelligent than an army of Einsteins..."
Eterno is a massive and all-powerful android constructed on Earth by aliens known as XANs one billion years ago. When the XAN were threatened by space gas, Eterno journeyed to the earth's core to retrieve the element Absorbium. However the Absorbium deactivated Eterno and the XAN perished. Eterno remained entombed in solid rock.
Eterno is re-awakened by three members of the Superman Revenge Squad to serve as their monstrous minion against Superman. Unfortunately for the evil Squad, after a titanic battle with Superman, Eterno turns on them, and a collison between the Squad's ship and the robotic colossus leads to the destruction of both the Revenge Squad members and the mechanical marvel (Act No. 343/1, Nov 1966: "Eterno, the Immortal!").