> Fink typically doesn’t deal with vault toilets in Wyoming’s state and national parks, but he knows what horrors can lurk at their depths. This man was lucky he wasn’t down there deeper or longer, he said.

In terms of fears, I still remember the X-Files episode [0] where the murderous creature hides in the septic system of a toilet, before escaping onwards through a hose into the collection vehicle.

[0] https://en.wikipedia.org/wiki/The_Host_(The_X-Files)