Zilla (Super Robot Jet Jaguar)

Zilla (ジラ, Jira) is a giant mutated marine iguana monster that is featured in the animated series Super Robot Jet Jaguar.

Appearance
Zilla is 90 meters tall, 180 meters long, and weighs 20,000 tons. Zilla stands bipedally, but hunched forward like a dinosaur, though occasionally he walks upright. Zilla has dark blue skin on the top portion of his body, with brownish skin on his underbelly. Zilla has a long rectangular head with a large underbite, three rows of forward-pointed scutes on his back, two smaller humanoid forelimbs, and long powerful hind limbs.

Pre-Series
In 1968, the French government conducted a nuclear test in secret on an island in French Polynesia. The test proved successful, decimating seemingly all flora and fauna on the island, and leaving nuclear fallout in its wake. What the French were unaware of however, was that something had survived the test. Unbeknownst to the French government, 15 breeding pairs of marine iguanas had recently been introduced to that particular island by an independent scientific organization. The iguanas thrived in this new habitat, and one particular beach on the island was littered with their nests. The nuclear test eradicated this iguana population, but one egg remained in the radioactively polluted sand. Not only did the embryo inside the egg survive, but the fallout heavily mutated its genes. When the iguana hatched, it required massive amounts of food to sustain itself. It began eaiting irradiated fish and seaweed from nearby waters. The iguana grew to incredible size over the next three decades, and developed bizarre anatomical mutations, such as a bipedal gait and three rows of huge dorsal scutes.

A Night of Horror in New York
By 1994, the creature had grown to nearly 300 feet in height and required even greater amounts of fish to sustain itself. The creature swam away from its island and into the middle of the Pacific Ocean. There, it intercepted a Japanese fishing boat full of thousands of fish. The creature destroyed the vessel and fed on its catch, then swam south toward South America. When the ship's wreckage was recovered, all of the signs pointed to Godzilla, who was believed to be dead, being responsible for the attack: the bite marks, the radioactive fallout, and the only survivor recovered from the ship, when asked about what caused the wreck, responded "Gojira" over and over again.