Dan and Stan are sent to a lost island to rescue a wealthy pair of treasure hunters. The adventurers encounter a tribe of sexy jungle girls who worship a flesh-eating T-Rex.

After becoming injected with a formula derived from an alien ship, a lab gorilla escapes from his containment and befriends two young boys. The alien formula causes the gorilla to grow to gargantuan size and rampage throughout the city and the boys must find a way to save their simian friend before the army takes him down.