Godzilla (2010 Marvel Animated Universe)

Godzilla is a giant mutant dinosaur created by Toho.

He appears in Marvel's Godzilla vs the Avengers, Marvel's Godzilla vs the Squadron Supreme and Marvel's Godzilla: King of the Monsters.

Origin
Godzilla was a dinosaur that survived the extinction and gets mutated by nuclear radiation.

War against the Avengers
Godzilla has been sighted around the globe and attacks a nuclear power plant in Japan. He then swims towards New York to wreak havoc and battles the Avengers.