Since the first three Spider-Man films took the best Marvel bad guys from Spider-Man, the Amazing Spider-Man went more for the 2nd string. The Lizard was never my favorite in the comics or cartoon, but I liked him here.
This incarnation is about the same as any other. He’s a brilliant scientist with only one hand. He meshes his own DNA with reptile genes to grow his hand back.
Which gives him a new hand, but he goes crazy and turns into a monster known simply as The Lizard.
He wants to turn everyone into monsters like himself to “cure” everyone, for which Peter Parker vows to stop him. They had a pretty decent fight.
He is turned mostly back human thanks to Spider-Man and Gwen Stacy’s help at the end. He apparently knew the truth about Peter’s parents, for which he tells an evil man questioning him to leave Peter Parker alone while he sat in his prison cell.