A toilet where the seat is either too small or oddly shaped, resulting in your pecker not being able to stay below the seat as it usually sits when taking a dump. A Peak a Boo toilet can make for a very interesting bathroom experience.
"Yo Craig did you notice that Kyle has a Peak a Boo toilet at his house? My pecker was confused man."
"Wow there's my pecker...thanks Peak a Boo toilet!!!"