"The Testament of Atthamaus"

by Clark Ashton Smith 

originally published Weird Tales, October 1932

Atthamaus, the former executioner of the city of Commoriom, tells us how that city came to be abandoned by its citizens.

A particularly dangerous outlaw called Knygathin Zhaum has been menacing the countryside, leading a band of hairy Voormis in raids that involve not merely theft and murder but rape and "anthropophagism" (that's cannibalism to the uninitiated).  Even worse, its said that he is somehow related to the black god Tsathoggua.  Blech!

Anyway, Knygathin is captured and brought to the city.  He turns out to be completely hairless, but with patterned skin like a snake.  There's also a subtle sense of bonelessness or some such to his appearance, which Atthamaus finds particularly repulsive.

Well the big day comes and Atthamaus cuts off Kny's head - which spills not blood but a bit of black ooze, and reveals no normal bone structure.  Nevertheless he's dead.

Or is he?  The next morning, Kny is up and around town, and he eats a merchant whole for breakfast!  In front of witnesses!  

Well, Kny is promptly recaptured and the Hyperborean equivalent of double indemnity laws are set aside so he can get a second beheading.  He is buried again in a more extreme arrangement, but again the next AM he's back, eating one of the judges who sentenced him.

Realizing this is a bad scene, people start to leave town.  Kny is captured and beheaded again, his bod sealed in a sarcophagus and his head separated and placed under guard.  But that night a liquid gloop monster ("a dark, ever-swelling mass of incognizable matter, frothing as with the venomous foam of a million serpents, hissing as with the yeast of fermenting wine, and putting forth here and there great sooty-looking bubbles that were large as pig-bladders. Overturning several of the torches, it rolled in an inundating wave across the flagstones and we all sprang back in the most abominable fright and stupefaction to avoid it." - jeezus I'd have leaped back too!)

The gloop reunites with the head and Knygathin Zhaum is out of traction/back in action once again.  And he proceeds to eat some more people.  There's a mass exodus from the city and, realizing it is impossible to defeat Kny, Atthamaus joins the fleeing crowds...

Again, a synopsis doesn't quite do this justice.  You have to read Smith's acidicly flowery prose to really get the full experience.  The story is dark and suspenseful and gruesome - and also funny as hell.  Classic C.A. Smith.