Gamera vs. Zigra (ガメラ対深海怪獣ジグラ Gamera tai Shinkai Kaijū Jigura) is a 1971 Japanese kaiju film directed by Noriaki Yuasa. It is the seventh film in the Gamera film series.
Enraged, Zigra orders the woman to go to Earth and kill the children. She says it would be simpler to kill all the people of Japan, but Zigra tells her that humans must be preserved so they can be used for food. Now, Gamera, intent on discovering the identity of the alien interloper, flies in to save the day and rescues the children and their fathers. The UN authorities, after questioning Kenichi and Helen, resolve to attack Zigra. The Defense Force jets scramble, but the Zigran spaceship makes short work of them with its powerful lasers. The alien woman arrives on earth, disguised as a normal human, and begins her search for Kenichi and Helen. She hitches a ride with a Kamogawa Sea World dolphin trainer back to the facility, which the military is now using as its center of operations. She finds the two children, but before she can catch them they run away from her.
Gamera begins an underwater assault on the Zigran spaceship which transforms into a giant shark-like monster when hit by Gamera's flame breath. Zigra grows larger and larger and finally halts the heroic turtle with a ray that suspends his cell activity. Enervated, Gamera sinks into the sea. Zigra then makes contact with the people of Earth, saying that they should give up and surrender all the seas to him. Back at Sea World, the dolphin trainer and the facility's scientists discover a way to break the alien's hypnotic control with sonic waves. Thus, they manage to disable the Zigran woman, only to learn that she is actually an Earthwoman named Lora Lee (Chikako Sugawara in the Japanese version), who had been in a moon rover during the initial lunar attack and was captured and used by Zigra. Drs. Wallace and Ishikawa employ a bathysphere in an attempt to wake Gamera, only to find that Kenichi and Helen have stowed away on board. Zigra suddenly attacks them and again demands the immediate surrender of Earth or he will destroy the bathysphere. The UN commander reluctantly agrees to the alien's terms.
An electrical storm approaches the bay and a couple of lightning bolts revive Gamera, who stealthily takes the bathysphere from the sea floor when Zigra is not watching and returns it to the surface. Gamera and Zigra face off a final time and Zigra, using its superior versatility underwater, slices Gamera's chest with its blade-like dorsal fin. Gamera takes hold of Zigra, flies into the air with him and then drops him at high speed, slamming the alien monster onto the land. Zigra stands up awkwardly on his tail fins in order to fight Gamera. Gamera further incapacitates Zigra by jamming a boulder through its nose, pinning it to the ground. Gamera grabs another boulder and uses it, like a hammer on a xylophone, to play the Gamera theme on Zigra's dorsal fins. Finally, Gamera kills Zigra by setting his body on fire with his flame breath, reducing it to ashes in a massive conflagration.
Gamera vs. Zigra had a budget of 35 million yen which was roughly $97,000. Shortly after the film was completed, its production company Daiei went bankrupt leading it to be distributed by Dainichi Eihai.
Gamera vs. Zigra was released in Japan on 17 July 1971. The film was never released theatrically in the United States. It was released directly to television by King Features Entertainment in 1987.
The film was released on DVD by Shout Factory on 15 March 2011.
In a retrospective review, Slant Magazine noted the films "slipshod construction (even by the standards of films featuring actors in rubber monster suits)" which "suggests less in the way of a thought-out film than a product cranked out so as to fulfill a McDonald’s Happy Meal toy contract." The review concluded that Gamera vs. Zigra "isn't nearly as much fun as it should be, but for those with a cheeky fondness for city-scale monster mashes, there are some fleeting pleasures."