This phenomenon occurs when a toilet is not flushed for a long period of time and the urine and fecal matter is allowed to build up and fester to the point of growing it's own mold. This is most commonly found in poorly maintained convenience store bathrooms, but can also be found in any poorly maintained or rarely used bathroom facility.
You don't want to go in that bathroom, there's doo-doo-tee-tee-mold and it smells like something died in there and then took a dump.
This occurs when urine and fecal matter are allowed to fester in a toilet bowl until they begin to grow mold. While this phenomenon is rarely found, it can be spotted in poorly maintained convenience store restrooms or other areas where the toilets are almost never cleaned. The sight alone is very disturbing, but the odor is extremely offensive and has been known to induce gagging and/or vomiting. It can be difficult to remove the odor from clothes that have been exposed the stench and most people just throw them away. Other locations where this can be found include vacation homes (if the occupants forget to flush before leaving), abandoned buildings (occupied by gypsies), and frat houses.
I wouldn't go in there, there's doo-doo-tee-tee-mold and it smells like something died in there.