The Crime-Master
The Crime-Master was more like a wannabe master of crime. Nick "Lucky" Lewis was a minor mobster with big plans to unite the mobs under his rule, and used the identity of the Crime-Master as protection from retaliation. But an interfering Green Goblin and Spider-Man crashed his plans, and the Crime-Master was killed in a shoot-out with the police.
There's nothing notable about the Crime-Master. As far as Spider-Man foes go, he's a forgettable mobster, like the Lobo Brothers, Don Fortunato or the Big Man. I just really like the funky Steve Ditko design of his mask, and made the custom just for that.