When you drop a huge ass duce, and you wipe your ass, but there's nothing on the toilet paper. (so you end up wiping at least 5 more times to make sure, cuz u don't want swamp ass)
It's like magic. You shot it out .... and then it's gone
When you take a dump, and the poo has slid into the shadows of the toilet bowl, and cannot be seen. There's also nothing on the toilet paper when you wipe.
I just came back from the shitter, and I'll be damned if it wasn't a "poodini"...it was quite an illusion, cuz I coulda sworn a little turd slid out!