The Lizard is a comic book supervillain in the Marvel Comics universe, and an enemy of Spider-Man (however in his normal human state, he is an ally of Spider-Man). He first appeared in Amazing Spider-Man #6 (November 1963), and was created by Stan Lee and Steve Ditko. The Lizard is the alter-ego of Dr. Curt Connors, a human scientist whose fields of expertise encompass both herpetology and gene therapy. Connors' right arm had been amputated as a result of a war injury while he served as a medic in the military, and he later hoped to find a way to regenerate the lost or damaged limbs of disabled people. To this end, he studied the regenerative nature of reptiles and amphibians. He developed a radically advanced form of therapy which could reproduce these regenerative abilities in humans and began to use this therapy in experiments. Unfortunately, Connors was contaminated by his own serum and physically transformed into a bipedal, sapient reptilian humanoid. As The Lizard, Connors became a threat to humanity, with an insane determination to replace the human race with super-reptiles like himself. The Lizard possesses superhuman strength and durability due to his alligator-like hide. His regenerative powers give him incredible stamina, and he can fight for days without tiring. His tail is strong enough to cut Spider-Man's webbing and smash through solid concrete. The Lizard possesses the ability to scale walls like a gecko. He is also able to communicate with and control any reptiles within a one-mile radius, usually giving them simple commands such as attacking or guarding something. Although usually intelligent and capable of speech, the Lizard has several times reverted to a mindless, bestial savage state. The Lizard transforms back into Curt Connors. Art by Steve Ditko.Eventually defeated by Spider-Man and returned to his benevolent human self, Connors still transforms back into the evil Lizard to plague the web-slinger every now and then. Although repeated administration of the "Lizard formula" was originally required to change Connors into the Lizard, it was later revealed that great stress can also trigger the transformation. On several occasions the Lizard has retained the mind of Curt Connors and refrained from attacking Spider-Man or other people, but on the whole the Lizard can only be regarded as villainous in nature. When Connors' Lizard form is dormant, the scientist often helps Spider-Man in the event of serious medical or scientific problems. Even in his Lizard state he doesn't attack anyone he truly cares for, such as his wife Martha and their son Billy. After years of trying to cope with her husband's split personality, Martha Connors died of cancer caused by exposure to industrial toxic waste. Now Curt has the added guilt and stress of single parenthood while still fighting to control the monster within himself. http://en.wikipedia.org/wiki/Lizard_%28comics%29

wurt connor used dina form lizzards to get his arm back cos they have the ability ti regrow but the experiment went wrong and created the lizzard