The Acrobat. I wonder what he does…
Just in case his moniker isn’t a dead giveaway, he also describes himself as the world’s greatest acrobat, which seems extra redundant. He seems like he should be a support character in some kind of crime circus, but this guy actually had more than one outing as a villain. I don’t think he’s been spotted since the mid 60’s, though, so I imagine he’s at least retired by now.
References: [marvel.com: Acrobat]
[marvel.fandom.com: Acrobat]
Metahuman Database 