Goro

Once a normal monkey, Goroh was exposed to the drug Helypron Crystal G. The drug modified Goroh’s body, transforming the monkey into a towering ape behemoth. The creature escaped into the wilderness where it quickly became friends with the man of the same name as he. The two Gorohs stayed together as the ape’s hunger and playful nature made it start to take more risks. It began to swing from ropeways and attack passing milk trucks, quickly forming an insatiable appetite for milk.

However, as humanity grew tired of the ape’s recklessness, Goroh (human) was arrested and taken to Tokyo. The ape began to head into town to rescue his friend, but local authorities were quick to attack. As bullets tore into its body, Goroh was sent into a rampage! The ape began ripping apart the city until his friend was freed. Knowing he had to stop the ape’s rage, Goroh delivered it a canister of tranquilizer-laced milk. Drinking it down, the ape fell into unconsciousness. Unable to hurt anyone, the ape was relocated to a new island home, an island populated with other giant apes much like itself.

Trivia
The suit of the monster is actually a loosely disguised King Kong suit, from King Kong vs. Godzilla