When a space probe crash-lands on a far-flung Pacific atoll, the craft's alien stowaways decide to take over their new world one creature at a time. Soon, the parasitic life forms latch onto three indigenous critters -- a squid, a crab and a snapping turtle -- and transform them into colossal mutant monsters.
久保明
as Taro Kudo
小林夕岐子
as Saki, native girl
高橋厚子
as Ayako Hoshino
土屋嘉男
as Dr. Kyoichi Mida
中村哲
as Chieftain Ombo
堺左千夫
as The Editor (uncredited)
佐原健二
as Makoto Obata
藤木悠
as Promotion Division Manager (uncredited)
Noritake Saito
as Rico, the guide (uncredited)
当銀長太郎
as Yokoyama, an agent (uncredited)
大前亘
as Sakura (uncredited)
Yukihiko Gondô
as Islander (uncredited)
