The Lizard by ProfessorAdagio
Please note, the image above is the result of my fan edit/manipulation which is my attempt at making the image have a different look and feel to the original. The original work can be found in the link below.
Curtis "Curt" Connors was born in Coral Gables, Florida. He was a gifted surgeon who enlisted in the U.S. Army and was sent off to war. He performed emergency battlefield surgery on wounded GIs, but his right arm was injured in a blast and had to be amputated. After his return to civilian life as a research technologist, Connors became obsessed with uncovering the secrets of reptilian limb regeneration. Working from his home in the Florida Everglades with the help of war buddy Ted Sallis, he finally developed an experimental serum taken from reptilian DNA. He successfully regrew the missing limb of a rabbit and then chose to test it on himself. Connors ingested the formula and his missing arm did indeed grow back. The formula had a side effect; Connors was subsequently transformed into a reptilian humanoid monster. Spider-Man discovered this situation during a trip to Florida to investigate newspaper reports of the Lizard after the Bugle challenged him. Spider-Man was then able to use Connors' notes to create an antidote to restore him to his human form and mentality. Another attempt to develop this serum for safe use again resulted in Connors transforming into the Lizard, but on this occasion he was saved thanks to his former colleague Professor Charles Xavier and his first team of X-Men, Beast and Angel tracking the Lizard down in the swamps so that Iceman could send him into hibernation long enough to develop a cure.