Person who has a poo that explodes like a pyroclastic flow out of a volcano, causing large amounts of shit stains all over the bowl. When the toilet is flushed the water does not reach all the shit stains.
The person also does not have the decency to clear up afterwards. The smell afterwards is so putrefying that it makes your nose bleed.
OMG don't let that girl use your toilet, she's a shit-monster!!
looks like the shit-monster has struck again!!