Frankensteinin saari was released in the year 1967。Frankensteinin saari is also called as Kaijûtô no kessen: Gojira no musuko, Son of Godzilla, Monster Island's Decisive Battle: Godzilla's Son, Hijo de Godzilla, Godzillas son, Frankensteins Monster jagen Godzillas Sohn。

On a tropical island, scientists are conducting weather experiments and encounter gigantic mantises and a giant spider that are attacking the son of Godzilla, who arrives to defend his offspring.