Godzilla was a lizard mutation created by French atomic testing, which instinctualy set out for New York City to feed and reproduce; this Godzilla was asexual, and layed eggs at madison square garden. The creature was called "Gojira" by Japanese fishermen who encountered it, but the name was garbled into "Godzilla" by American TV journalist Charles Caiman. After several conflicts with the U.S. military, during which most of its offspring were destroyed, it was finally slain.
This Godzilla was smaller than its counterparts and, while being radioactive, it had no true atomic breath(thouh its breath was apperantly flamable). Its unusual speed for its size, as well as swimming and tunneling ability, were some of its other assets.
Godzilla had one surving offspring, which (after imprinting on Dr.Nick Totopolus) was raised by humans and helped protect mankind from other mutations. It had true atomic breath, unlike its parent and was sterile.
this incarnation existed in one of the Millennium continuities, specifically in "godzilla final wars"(under the name of "zilla")and aparently also existed in Godzilla, Mothra, King Ghidorah: Giant Monsters All-Out Attack as in the opening scene refrence is made to a creature that attacked New York and was mistakin for godzilla.