Mothra vs. Godzilla is a 1964 Japanese kaiju film directed by Ishiro Honda, with special effects overseen by Eiji Tsuburaya. Produced and distributed by Toho Co., Ltd., it is the fourth entry in the Godzilla franchise. The cast includes Akira Takarada, Yuriko Hoshi, Hiroshi Koizumi, Kenji Sahara, and twin actresses Emi and Yumi Ito, with Haruo Nakajima and Katsumi Tezuka performing inside the Godzilla suit. The premise places humanity in the position of appealing to the divine moth Mothra for help in stopping Godzilla from devastating Japan.

Following the strong performances of Mothra in 1961 and King Kong vs. Godzilla in 1962, Toho decided to bring the two iconic monsters together for the next installment. The film was designed to appeal to both children and adults as part of an effort to compete with the rising popularity of television in Japan. A new Godzilla suit and a new Mothra prop were constructed for production, though the 1962 Godzilla suit was retained for use in water sequences and a shot of Godzilla falling from a cliff. At Tsuburaya’s urging, Toho invested in an Oxberry 1900 optical printer to clean up visual artifacts that had been appearing in composite photography work.

The original story concept was conceived as a continuation of the Mothra film, recasting the Rolisicans, the fictional inhabitants of the fictional nation of Rolisica, as the antagonists.

Screenwriter Shinichi Sekizawa’s earlier drafts differed from the finished film in a number of significant ways. The villain Torahata was absent. Sakai was accompanied by two scientists rather than one. It was Godzilla’s body that washed ashore rather than Mothra’s egg. The lead characters offered themselves as hostages to the people of Infant Island in exchange for Mothra’s assistance. Godzilla was to attack Rolisica rather than Japan, with the Frontier Missiles operated by Rolisican forces. Himeji Castle was slated for destruction. Godzilla would have pushed eastward all the way toward Tokyo, and the electrical tower sequence in the city would have inspired the characters to develop the artificial lightning tactic. Mothra would have entered the fight when Godzilla proved immune to electricity, and the final confrontation between the two monsters would have taken place on a beach while Godzilla was pursuing the lead characters.

Honda significantly reworked Sekizawa’s draft to reflect his own creative priorities. A speech delivered by Sakai about the brotherhood of humanity, absent from Sekizawa’s script entirely, was written by Honda and added during production.

The score was composed by Akira Ifukube, who incorporated elements from Yuji Koseki’s Mothra theme from the 1961 film. Honda and Ifukube worked closely together, holding planning sessions to determine which scenes would carry music. They disagreed over a moment in which Godzilla rises above a ridgeline. Honda wanted aggressive accompanying music, but Ifukube pushed back, arguing that Godzilla’s presence alone was sufficiently commanding and needed no musical reinforcement. Godzilla’s theme was ultimately added to the scene, a decision that left Ifukube dissatisfied. A piece titled The Sacred Springs was the only music Ifukube composed specifically for the Peanuts, the twin fairies who serve as Mothra’s emissaries, and was written to express mourning for the destruction of Infant Island.

For a 1980 reissue, the Japanese pop and rock band Talizman recorded a new song simply called Godzilla, which was later included as a bonus feature on Toho’s 2014 Blu-ray release.

Special effects direction fell to Tsuburaya, with Teruyoshi Nakano serving as his assistant. Mechanical props and puppets were fabricated for both monsters.

The Godzilla suit was built by Teizo Toshimitsu two months before filming began, with suit actor Haruo Nakajima visiting the workshop and providing feedback during construction. The finished suit was lighter than its predecessors, giving Nakajima greater freedom of movement, and reinforced heels allowed him to roll and flip without losing his footing. The 1962 suit was brought back for the water scenes and the cliff sequence.

A new Mothra prop was constructed along lines similar to the 1961 version. Y-shaped braces attached to its back drove wing movement powered by high-speed fans, and the prop’s wingspan measured fifteen feet. Remote-controlled mechanisms allowed the head and legs to move independently. The Mothra larvae were operated through a combination of hand puppetry and motorized mechanical rigs. Their silk webbing was produced from liquefied polystyrene. In off-screen shots, the liquid was poured into a cup placed at the center of a heavy industrial fan, with the cup sealed except for small gaps around its edges. To fire the web from the larvae’s mouths, compressed air was pushed through a sealed tube of liquid polystyrene; the pressure forced the liquid through tubing running inside the larvae and out through nozzles in their mouths. At sufficient pressure through a narrow nozzle, the solution vaporized as it emerged and solidified into web strands on contact. Gasoline was required to clean off the residue afterward.

For the scene in which the larvae wrap Godzilla in silk, rubber glue was blown onto the Godzilla suit using an electric fan. During filming, the glue hardened and proved extremely difficult to remove.

During the firebombing sequence, liquid fire splashed onto the head of the Godzilla suit. Nakajima was unaware of it happening, as his head was positioned below the suit’s neck, and the unscripted shot was retained in the final cut.

In May 1964, producer Henry G. Saperstein acquired the American theatrical and television rights under the working title Godzilla vs. the Giant Moth and sold them to American International Pictures. AIP opened the film in Los Angeles on August 26, 1964, releasing it as Godzilla vs. the Thing, a title deliberately chosen to build curiosity and suspense around Godzilla’s opponent. AIP commissioned artist Reynold Brown to design a poster that featured Godzilla but obscured the other monster entirely. Brown received $350 for the work.

For the American release, Toho shot additional footage showing the United States military assisting Japan through the use of Frontier Missiles. The American cut also trimmed the Shobijin song performed on Infant Island and shortened a farewell scene in which several characters wave goodbye as the Mothras depart for home. Removed entirely were a scene showing Kumayama distributing promotional leaflets for the giant egg incubator and a scene in which Torahata shoots Kumayama inside a hotel room. The American release was paired as a double feature with Voyage to the End of the Universe and dubbed into English by Titra Studios.

This film marked the last time in the classic Godzilla era that the monster was portrayed as a straightforward villain.