The Maniacs are a criminal gang in the world of Champions Online MMO.
Maniacs are known for their eccentric outfits, described best as homeless clown. They're not splashy or flashy as you would expect a clown-based villain group to be. Rather, they're grim and gritty and dirty. And they smell. What do you expect from a group that make the sewers their headquarters?
You can especially see them around Leo's Bar, which is a known Maniac haven.
(See their entry in Champions Wiki for more information.)
Their ongoing gang feud against the New Purple Gang was shown in "Battlerock Comics Presents" #2.