We don't know what "death" means for the infected Cooper, per se, except that he's now chow for the other demons. We've seen a few "demons," for lack of a better term, on the show so far. They're coated in black and you can usually spot them by the whites of their eyes. When Cooper left the federal prison, a demon (a woodsman?) slunk out just behind our antagonist. When Killer Bob version of Cooper dies, the demons come running, seemingly to feast on the body. They rip him apart with their hands, leaving a bloodied body on the ground. It's nice to have Ray there as witness during this moment — he's visibly perturbed, which tells us that this is Not Normal. Ray is by no means a "good guy" on this show, but at least he's not in cahoots with these folks. ("I saw something in Cooper. Maybe the key to what this is all about," he says on the phone on his way out. It's like David Lynch needed to cover his bases, let us know that the "demon feasting" moment was rather key.)