Curtis Connors (Earth-4678)

Doctor Curtis "Curt" Connors was a medic in St. Martin Hospital who helped Peter Parker when he injured his shoulder.

Biography
At an unknown point in both Curt and Peter's life, Curtis became a humanoid reptile that would become one of Spider-Man's earliest foes until Peter created a cure using Curt's blood. The cure only worked temporarily, however, and it appeares that the Lizard was still roaming around somewhere in New York. Peter kept the vial of blood as a memento.

Source

 * https://marvel.fandom.com/wiki/Curtis_Connors_(Earth-1048)