The Lizard

Doctor Curtis Connors - also known as The Lizard - is a mutated villainous character from Marvel Comics. He is a recurring opponent of Spider-Man.

Biography
Curtis Connors was a renowned biological scientist and a former frontline surgeon in the US Army. At some point during his service, he was badly injured by shrapnel. He survived, but his right arm had to be amputated.

Since losing his arm and leaving the service, Connors devoted his life to science, most notably genetics. He grew obsessed with reptiles and their capacity for healing injury and regrowing lost limbs, studying them in-depth. Still agonizing over the loss of his arm, Connors became fixated on harnessing the healing properties of reptiles and spent years developing a serum that utilized lizard DNA which he believed could regenerate his arm. Ignoring the warnings of his wife Martha, Curt injected himself with the serum.

Initially, the experiment seemed to be a success: the serum did indeed restore Curt's lost arm. However, the serum did much more than grant Curt reptilian healing; the lizard DNA bonded with and overwhelmed Connors' human biology, mutating and transforming him into a reptilian monster.

Connors - being dubbed "The Lizard" by the media - completely lost control and went on a rampage. However, he would be stopped by Peter Parker, aka Spider-Man, who studied Connors' research and was able to develop a counter-agent, a gene-cleansing formula that restored Connors to his human form... for a time.

Ever since his initial experiment, Dr. Connors has been forced to live a double-life. The serum that Spider-Man made to cure him only had a temporary effect as the reptilian DNA in his body has proven to be highly adaptive, mutating to resist whatever attempt Connors makes to remove it from his system. Whenever Connors becomes overly stressed, he runs the risk of transformation.

Personality
Curt Connors and the Lizard are of the same body, but not the same mind. Curt himself is typically mild-mannered; he is a family man with a wife and son and cares for them deeply, though his passion for science and his obsession over his condition can result in him becoming distant from others.

Each time the doctor transforms, he undergoes a radical personality change. The Lizard's mental state has often shifted between being primitive and violent to being calculating and sinister. In his more intellectual state of mind, the Lizard has displayed a cold and unsympathetic attitude towards humanity as well as a hunger for power and control. He has consciously and willingly committed many violent crimes and even attempted to take over the world on several occasions.

Powers and abilities

 * Genius Intellect - Connors is a gifted scientist and surgeon and usually retains his remarkable intellect when he transforms into the Lizard. He does not, however, retain his own personality. The Lizard has used his superior intelligence to commit several heinous crimes, both in the name of science and to satisfy his own vicious appetites. His intellect is often hampered by his reptilian bloodlust and he is prone to violent outbursts.
 * Superhuman Strength - As the Lizard, he has superhuman strength enabling him to lift/press 12 tons, speed, agility, and reflexes equalling that of Spider-Man. He possesses great resistance to injury surpassing that of Spider-Man in that his tough scaly skin is more resistant to being lacerated or punctured by concussive force.
 * Reptilian Healing - The Lizard is highly resistant to disease and infection, can rapidly heal any wound and can even fully regenerate lost limbs. When he turns back into Connors, his right arm atrophies and recedes, only growing back when he transforms.
 * Telepathy - The Lizard has also developed the ability to mentally control and command other reptiles, using them to protect him when he needs to.

Weaknesses
As a cold-blooded reptile, the Lizard prefers hot and humid environments and despises the cold. Prolonged exposure to the cold will slow him down and weaken him.

The Lizard's only other notable weaknesses are his unpredictable mental state and also chemical and biological agents specifically concocted to restore his humanity. Such formulas have never had a permanent effect on him, however, as his reptilian biology keeps adapting to resist them.