Fandom: Creepypasta

EJ's fingernails double up as retractable claws. His claws contain a toxin very similar to anesthesia (the stuff they give you to numb you and make you sleep during surgeries). This makes cutting out the kidneys of his victims much easier and it comforts him knowing that at the very least, they couldn't feel him meticulously removing one of their organs.

He can also see because of the cult sacrifice he was in. The demon(s?) in his body give him several inhuman abilities including his previously mentioned claws, fang-like teeth, three extendable incredibly strong tongues and heat signature based vision.

Jack doesn't like eating kidneys, contrary to what most Creepypastas believe. He's disgusted by the fact that he eats what he used to be (I mean, he was in a cult sacrifice and is a demon, so he's not human anymore, right?). Because of that, he doesn't like getting close to people (he doesn't want to end up eating them) and only eats when he absolutely has to (human food doesn't sustain him for very long) which is why he's so skinny (but, I also see him as a fairly lean muscular individual).

Jack eats kidneys specifically because he can take them without killing his victims, but he can eat other organs if another Creepypasta lets him finish off one of their recent corpses.