The Lizard

When Dr. Curt Connors lost an arm in a lab accident, he tried to use reptile DNA to find a way to re-grow his missing limb, the way reptiles are capable of doing. But a miscalculation in the formula instead transformed him into a monsterous human-reptile creature known as The Lizard!

The Lizards attempts to transform the entire planet's population into a race of reptile-human hybrids have been stopped time and again by Spider-Man. Over the years, Connors has found ways to transform back into his human form, but every time the Lizard returns, it's become more and more dangerous.

Goin' Green
The Lizard was an Alternate, entering the tournament in round 2, and being immediately eliminated by Mike Wazowski