Skrillex is part of a wave of American producers coming into dubstep from other genres. More often than not, these beatmakers make a violent racket characterized by overwhelming midrange "wobble" basslines, and have a general obsession with gore, macabre and the almighty "filth." It's "mosh" music as opposed to dance music.
He lends his music miles away from the garage and dub-inspired scenes in the UK.
His sound is overbearingly plain and simple. While he has a firm grasp on melody that eludes many of his peers, they're usually coated in headache-inducing layers of abrasive muck. The trancey hook of Scary Monsters and Nice Sprites' title track is equal to nails on a chalkboard, and the less said about its onomatopoeic bass growls the better.
My friend totally agrees that Skrillex sounds like a cat getting fucked up the arse with a jackhammer.