A statement made when one urgently needs to take a large dump. This is a visual reference referring to a piece of feces (the turtle) hanging out of the rectum, and "sniffing" one's underpants. This can also can be used to describe the moments prior to soiling yourself.
Brad: "Hey Alice, let's go have sex!"
Alice: "Hell no, after eating that egg salad the turtle is sniffing the cotton"
Carl: "Forget the roller coaster guys, the turtle is sniffing the cotton"
Alice: "Hell no, after eating that egg salad the turtle is sniffing the cotton"
Carl: "Forget the roller coaster guys, the turtle is sniffing the cotton"
by rimlover October 30, 2010
When you unsuccessfully attempt to hold in a turd and the end pokes out into your underwear, generally resulting in a skid mark.
by Beamer from Hell September 09, 2008