A backpack stuffed with couch pillows (or other large, soft items) worn by overly-intoxicated individuals to ensure the prevention of inhaling vomit while passed out. This pack is generally applied by the user's less-drunk, responsible peers.
"Damnit! Taylor is wasted, don't you think he might inhale his vomit and die while passed out?"
"No man, let's just put the drunk pack on him"