Porcelain Ricochet

The guttural and oft deafening resonance created when ass gas breaches the O-ring, slams into toilet water and bounces off the bowl. The resulting sound is both ghoulish and unholy.

My God! We better get the hell outta here. I was just in the Library bathroom and heard a porcelain ricochet that could only have come from a Yeti or a Nazgûl. Either way, I'm not sticking around to find out.