Still reeling after the hard-fought battle to repel Legion, Japan is now reminded of a deadly foe from the past. The Gyaos have returned. And this time the ornery man-eating birds have not only increased their numbers, but they have also added a new menacing member to their destructive little club. Iris, the flying, blood-sucking squid monster, is all rested up and ready to rumble. Raised by a young girl whose parents were squished by Gamera in a horrible accident, Iris takes her learned hatred and goes out on the warpath. Dr. Nagamine (Shinobu Nakayama) and Inspector Osaka (Yukijirô Hotaru) are reunited to help Gamera in his relentless quest to protect and save the human race. Can Gamera ground the Guayos? Can the turtle tie up the terrible tentacles? Do the hapless humans and the rowdy reptile have what it takes to thwart the revenge of Iris?