When sitting on the toilet for so long that ones legs fall asleep.
Frank, are you almost done in there, your going to end up with shitter legs!
Fake legs to put in the stall next to you so no one sits in that stall and you can shit in peace.
Anthony was fed up from people shitting in the stall next to him so he made some shitter legs to place in the stall next to him to make it appear it was being used.