Originally referred to as Godzilla in the 1998 film (and referred to as such in merchandising specific to that movie), due to how unfaithful the kaiju was to the original Godzilla compared to the original source material, particularly being designed a lean and relatively small (for a kaiju standard) lizard-like creature, compared to the established theropod-like kaiju design of the original Godzilla, the kaiju would be adapted into "Zilla" by Toho for later appearances.
It has been such a subject of ridicule by Toho and fans that Toho's adaptation of the kaiju as Zilla, appearing in Final Wars as an entirely different species, would see it be beaten by the original Godzilla in 13 seconds. Due to rights issues surrounding the 1998 film, Zilla has been used to refer to that movie's version of Godzilla in international merchandise.
