one big group cuddle that usually consist around 4+ people;
laying (usually resting your head) on a part of someone (stomach, thigh, chest, ect.) while they lay on a part of someone else, and you let someone else lay on a part of you.
bro, do you wanna start a penguin pile on the dancefloor?
c'mon let's join the penguin pile!
you: why are all those people laying in the middle of the floor?
me: they're penguin piling, duh.
When you get separated from your wife at the zoo and end up locked in the penguin exhibit and are lonely and horny looking for companionship and the only thing around is a group of furry penguins that ultimately ends up in some kind of fucked up inter-species orgy.
I got separated from my wife at the zoo so I got in a penguin pile.