Ass. In Who's Undercover, Big Pie Face and Ass PK's is a funny type of game, hence the ass. "Who is undercover" is a very interesting, popular nationwide competition of verbal expression ability, knowledge and imagination of the game, "Who is undercover" is a competition of verbal expression ability, knowledge and imagination of the game. The rules of the game, the presence of seven players, of which six players are taking the same words.