The turd peeker is similar to a turd burglar. The main difference however, is that while a turd burglar will actually try and open the stall you are in, the turd peeker will enter the bathroom and walk slowly along the row of stalls, peeking between the cracks at all who are shitting. Much like turd burgling, this activity leaves the shitter feeling violated and uneasy.
I was shitting in the mall bathroom the other day when suddenly a turd peeker walked up to the stall I was in and put his eye to the crack... I felt so violated.