Source: marvel.wikia.com
7. Ringmaster
I swear to god, "˜60s Marvel had a weird circus fetish. To quote myself from an earlier article, "It's like the Marvel universe economy was 30 percent circus-based."
Ringmaster was the head of the Circus of Crime. The plan was simple: the circus of crime would go from town to town, performing. At the end of the show, Ringmaster would use his hypnosis hat to freeze the audience while the rest of the circus would"¦um"¦rob everyone. Okay, I lied, the plan was very much not simple.
Y'know, Ringmaster, it doesn't really seem like you need all those other guys. It also seems unnecessary for you and your crew to put on a full circus show for every robbery. Just, like, walk into a bank with your hypnosis-hat and rob them.
Look man, I'm just trying to reduce your operating costs here.
Anyhoozles, the Ringmaster was eventually beaten down by the first ever Spider-Man/Daredevil team-up. They skulked around the corners of the Marvel Universe for a while before disrupting Hank Pym and Janet Van Dyne's wedding, which is really more of a heroic move, to be honest.

