Gollum puts his finger in the ass of the victim and tries to make them squirm. Then everyone tries to guess who the victim is by going one at a time, in order. If they guess correctly Gollum wins and goes again, if they guess wrong then the victim wins and becomes Gollum. There is strategy in who you pick if you're Gollum, if you pick someone too early in the order they might be able to hold their composure. If your pick someone too late then people have more chances to guess the wrong person before they get to the victim.

It's a lot like Among Us except everyone is naked and one of the crewmates has a finger in his ass.