The Septicmans is a unique subset of mysterious ningen that subsist off of rubbing themselves with filth and sewage. They submerge themselves in filth so that we don't have to. Septicmans are not to be seen, but it is the Septicmans who do the seeing. For this reason, natural philosophers have had much difficulty studying the particulars of the septicmans. Septicmans are usually only discovered by persons fortunate enough to spot the septicman staring back at them from a cesspit or toilet's drain. Appearances of the septicman have been compared to that of a normal ningen in a gimp suit but it is unknown if the gimp suit is actually a suit or a septicman's natural skin.

Cryptologists have rallied and conducted various billion dollar expeditions to bathrooms, particularly Burgburger ones, in the hopes of finding septicmans. The searches have been fruitless. The only thing known about septicmans is that their ultimate weakness is when people eat very spicy foods, particularly the cuisine of Ramastan. Most documented cases of septicman deaths involve a Hard Man taking a large dump and having his japaleno-laden stools burn the septicman to death. These instances are the only cases in which septicmans can be heard through their shit-curdling screams as they melt into nothingness.

Septicmans are the sworn enemies of Boogal.