Zag'Thuk is the lord and father of the Shaggrin, having sacrificed a part of his essence for their survival.  His new form is a mere piece of what he once was.  He appears as a hulking lizard, with massive talons and sharp spines running down his length.  His long, muscular neck ends with a viper-like head, with retractable fangs lodged within his skull.  The most impressive part of his visage are his colossal wings, which span 100 feet and are covered in hardened quills.

Zag'Thuk's lair lies within its own plane, known as the Brink.  The Brink was created when Zag'Thuk sacrificed half of his essence to save the Shaggrin, and as such became bound to a new realm.  The Brink is an area made up of both the Abyss and the Material Plane, where Zag'Thuk sleeps protected by his most devout servants.  The layer itself is simply known as the Primordial Nest, a sprawling pit made up of unknown species of plants.  Scattered throughout are naturally grown structures, within which live the families of Zag'Thuk's holy warriors.  The center is a raised platform of entwining vines and roots, at the center of which resides the nest of Zag'Thuk, where he lays the eggs that hatch his new Shaggrin guardians.

The challenge rating of Zag'Thuk is 24 when he is encountered in his layer.

Layer Actions

On initiative count 20 (losing initiative ties), Zag'Thuk can take a lair action to cause one of the following effects; he can't use the same effect two rounds in a row:

• Zag'Thuk roars, causing 1d10 eggs in his nest to hatch into fully grown Shaggrin Servant of Zag'Thuks.  
• Zag'Thruk chooses one humanoid, and turns it into a Shaggrin Servant of Zag'Thuk.  This copy becomes destroyed on the next initiative count of 20.  (This ability can only be used once).
• Zag'Thruk lets out a primal roar across time.  Each creature present that is not a Shaggrin must succeed on a DC 22 Wisdom saving throw, or take 5d10 force damage, and become Paralyzed for 1 minute.

Regional Effects

The Brink is warped by the magic containing it, seeing as it was not naturally conceived.  The magic creates one or more of the following effects.

• Creatures within 1 mile of Zag'Thuk with a wisdom score below 18 begin to think that they are aging backwards, slowly becoming younger.  After 12 hours of exposure, they actually begin to age backwards, causing them to lose proficiency in everything and making their ability scores drop by 2 every hour; their hit points drop by 75 every hour.  If they reach 0 hit points, or if 3 or more of their abilities drop to 0, then they cease to exist.
• The Brink is constantly changing, making it nearly impossible to navigate.  
• If any intelligent creature spends more than 1 hour in any square mile of the brink, then they must succeed on a DC 23 Wisdom saving throw, going mad on a failed save (see madness of Zag'Thuk).  A creature that succeeds on the save cannot be effected by the madness for another 24 hours.

If Zag'Thuk dies, these effects disappear over 1d6 days, and the Brink collapses in on itself and is destroyed permanently the next day.

Madness of Zag'Thuk

If a creature goes mad within Zag'Thuk's layer or within the demon lord's line of sight, roll on the following table to determine the nature of the madness, which is a character flaw until cured.

Roll on a d100.

01-20: "I secretly believe in the legends surrounding Zag'Thuk...I plan on killing my friends in order to ascend to a higher existence within the Brink."

21-40: "There is no life and death, only existence.  Before birth, we merely exist.  In life, we live.  In death, we go insane."

41-60: "My bearing on reality is falling apart.  Every night, I no longer have dreams, but visions of the Brink...I somehow think it will tie into my death."

61-80: "I am prone to violence, some much so that I have a need to consume the flesh of my comrades."

81-100: "I feel that I am the answer to the existence of the Brink, the Shaggrin, and Zag'Thuk.  The Brink is merely a warning from the gods of our universe."