Due to the film's great box office success, Toho planned to produce a sequel titled "Continuation: King Kong vs. Godzilla", but the project was later cancelled. Toho later conceived the idea to pit Godzilla against a giant Frankenstein Monster and assigned Takeshi Kimura in 1963 to write a script titled "Frankenstein vs. Godzilla". However, Toho rejected the script and instead matched Mothra against Godzilla in "Mothra vs. Godzilla". This began a formula where "kaiju" from past Toho films would be added into the Godzilla franchise. Toho was interested in producing a series around their version of King Kong, but were refused by RKO. However, Toho would handle the character once more in 1967 to help Rankin/Bass co-produce their film "King Kong Escapes", which was loosely based on a cartoon series Rankin/Bass had produced.