Look who I saw in Ben 10 Omniverse: three Goth cameos in one. There's Raven, Jinx, and loligoth Stocking from the anime Panty & Stocking with Garterbelt. Like Gwen Tennyson, they are students of the esoteric Friedkin University. They are usually seen under grey hoodies because they belong to a secret allied group of the villainous Darkstar.
"Finally! I've been waiting (mumble, mumble)"