Trespasser (World War Monster)

'Trespassers' is the name given to a species of massive, amphibious extraterrestrial creatures that arrived on Earth in a meteorite in 1945. One of the most destructive creatures ever encountered, the Trespassers are directly responsible for the formation of the New Peace.

Biology and life cycle
Trespassers have an extremely unique biology,  They are nitrogen-based, and their bodily fluids are highly toxic, in particular their blood. Trespassers are colossal creatures, averaging hundreds of feet in height and hundreds of tons of weight.

Being amphibious, Trespassers are highly adaptable to both land and underwater (although due to their bulk, they are significantly sluggish on land, especially when in confined areas, such as cities).

Trespassers appear to be drawn to cities due to costal run off, and examinations of their biology indicates that they gain sustenance from chemosynthesis; feeding off various toxic chemicals.

Life cycle
Trespassers have a very unique life cycle that has been likened to metamorphosis. Every known Trespasser encountered has been hermaphroditic, reproducing asexually via parthenogenesis.

Trespassers began life as microscopic, single-celled organisms. While in this state they are largely inert and harmless, having been likened to phytoplankton, drifting along ocean currents.

Although these microbes can lie dormant for years, until under certain circumstances--which are still unclear to scientists--the microbes undergo a massive reproductive surge, likened to an algae bloom.

Once the 'bloom' reaches a certain density, the microbes began to form complex structures, eventually forming a fully grown Trespasser.

Trespasser intelligence
From the very first attack on Hiroshima, it was shown that Trespassers possess a type of intelligence, Little Boy was shown to anticipate attacks and even learned to use buildings as cover, while the surviving Trespasser, Fat Man, was capable of being trained.

Breeding and domestication
While highly destructive, efforts have been made to domesticate Trespassers for a variety of purposes, with limited success.