This fiend is born from lust and/or greed. Legend says that any human who lived its life full of greed and carnal desire before tending to the needs of others turn into the Gwarkabog after they've died. They are thought to dig up from the earth upon birth not far from where their former self died. Gwarkabog are often found on the outskirts of cities with large amounts of brothels or gambling halls.

If it remembers its mortal name at all from its former life it might only have a few obscured memories as well but it has absolutely no emotional attachments to these memories or in general. It only feels lust, greed, envy, and hatred. If a Gwarkabog sees another of its kind it'll immediately try to kill it and claim all its possessions as well.

Large, strong, humanoid, semi-gooey, and physically fire-resistant. This creature is usually dark brown or black in color allowing it to hide easily in dark places and in the ground. It's got large, flat, bat-like ears and beady cat-like eyes. Its fingers are extremely long, the tips of them and its toes are very sharp. Its chest is extra thick and fleshy.

This creature dwells in dark caves or cave-like areas usually in the mountainous regions, preferring volcanic mountains in particular.

It feeds off the insides of any animal/humanoid. It stealthily stalks its prey, sneaks up behind them and then pierces its long, tendril-like fingers into any orifices in their body to scoop out its lunch. It prefers the supple texture of brains and intestines in particular.

It lives just to live. It lives by its own rules. It is capable of speech, usually picking up the language of any large group of beings within the region of its lair if it doesn't already know the language already. It only ever uses language to mock, curse, or generally creep out its victims once it has them in its grasp before offing them.

Once it finds a "home" it's comfortable in, it's extremely hard to get it to leave. 

Its body generates quicker than a humans' and although it requires a lot of strength, it can be killed almost as easily. It will not die from old age.

This creature's lair is pitch black. It'll often have a hidden "treasure" consisting of various items (pieces of jewelry or strips of cloth) and body parts (favoring eyeballs) from its victims it found... interesting. If it gets bored of some of its treasures it either hide these items in a hole outside its lair or eat them.

Lair Actions

On initiative count 15, the Gwarkabog takes a lair action to cause one of the following effects; the Gwarkabog can’t use the same effect two rounds in a row:

• Slip: It can sneak behind to attack unless a successful DC 18 Wisdom (Perception) check is made
• Anyone inside its lair has a disadvantage on Wisdom (Perception) checks that rely on sight within 20ft

Regional Effects

The region containing a legendary Gwarkabog's lair is decimated within 100ft, which creates one or more of the following effects:

A natural burrower, within 20ft of this creature's lair are countless, loosely filled holes filled with its excrement. Anyone who falls into one of these must succeed on a DC 13 Dexterity saving throw to avoid acid damage. One of these can be spotted from a safe distance with a successful DC 16 Wisdom (Perception) check.

If the Gwarkabog dies, these effects fade over the course of 1 d10 days.