In almost the same way that octopuses do it for me, snakes are right up there as well. It has nothing to do with any actual or implied death, but with the constriction which I find to be very erotic. I mostly prefer the constriction that is slow and sensual, with a gradual buildup of pleasure and having the snake realize what feelings/emotions it is causing and focusing on enhancing any pleasure the target is getting from the situation.