There's so many to choose from. Could easily just name the entire Death Throws team, in part for their team's name being a terrible pun, in part because they're bad guys that commit their eveel deeds by way of juggling.


 Then there's the Gentleman Ghost... about as menacing as a sheet with a couple eye holes cutout.  

Horrifying

There's also the tragic Crazy Quilt:

Insane!

But I guess these two have been re-imagined recently to make them more modern, less incredibly lame. Gentleman Ghost got a nicer suit & pair of pants, a horse that breathes fire. Crazy Quilt got a pair of boobs. As if a female Crazy Quilt is any better.

But the character I most look forward to getting a modern, gritty revision-

Rooster-Man!..
I'm not sure if he was just an ode to the University of South Carolina mascot or a bored Steve Englehart finding a way to get the word cock into a CCA approved comicbook in 1975. Either way he's my greatest lame/silly villain pick.