20 Greatest Spider-Man Villains Ever

Much like Morbius, Doctor Curt Connors is a well-meaning scientist whose experiment went horribly wrong.

In this case, his attempts to use lizard DNA to regrow his lost arm caused Curt to transform into a humanoid reptile with a desire to turn all of mankind into lizard-people.

Spider-Man was able to stop him and reverse his friend's transformation, but that was far from the end. Curt constantly struggled trying to maintain his humanity against his cold-blooded impulses and often found himself transforming back into his reptilian alter-ego.

Things took a dark twist when the Lizard proved his lack of emotions by killing his own son. Curt's mind was fully restored soon after and he has been wracked with guilt ever since.