*nods* I've certainly seen some pretty batshit insane behavior from HP fans, but for all the bad reputation it's never struck me as wankier or crazier overall than other fandoms, it was just so big and so high-profile that the crazy was likelier to get epic, and spill out from the dark corners to where other people could easily point and laugh, while similar nutjobs in tinier fandoms toil away in relative obscurity.

And ero guro (http://en.wikipedia.org/wiki/Ero_guro) are "erotic grotesque", basically sexualized (up to and including flat-out hardcore pornographic) horror manga; link is to a safely non-illustrated brief Wiki article, but follow the links therein to artist's sites and imageboards at your own risk.