Zilla

Zilla (ジラ Jira) is a giant mutant iguana kaiju who first appeared in 1998 and later in 2004.

Origins
Zilla is a mutated French Polynesian Iguana that hatched from an egg that was exposed to a 1968 French nuclear test conducted in the Maruroa Atoll. The creature grew over a period of 30 years, and by the year 1998 had reached a size of about 180 feet as a result of its mutation.

History
In 1998, the Japanese fishing vessel Kobayashi-Maru was sunk at sea by a gigantic creature, leaving only a single survivor. The creature dragged the shipwreck ashore in Panama, leaving behind a trail of footprints across the island.

Out of universe information
Zilla first appeared as Godzilla in the 1998 TriStar Pictures film GODZILLA, and later the 2004 Toho Godzilla film, Godzilla: Final Wars.