Creature Sense. Kyuss is aware of the presence of creatures within 1 mile of it that have an Intelligence score of 4 or higher. It knows the distance and direction to each creature, as well as each creature’s Intelligence score, but can’t sense anything else about it. A creature protected by a mind blank spell, a nondetection spell, or similar magic can’t be perceived in this manner.

Magic Resistance. Kyuss has advantage on saving throws against spells and other magical effects.

Worm Growth. Kyuss can spawn worms periodically to corrupt other beings and slow them grow independently in power, when they reach a state of significant power they are drawn back to their source for Kyuss to absorb them and their additional power.  If Kyuss absorbs enough, he can grow in size.  There is no limit to how large he can grow if he absorbs enough creatures *DM Discretion.

Swarm. The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a worm. The swarm can't regain hit points or gain temporary hit points.

•  Multiattack: The demon makes two attacks with its tendrils and can use its Worm Infest once.
  • Tendril Strike: Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 18 (2d12 + 6) slashing damage.
  • Worm Infest (Recharge 6): The demon launches a worm at a creature within 60 feet. The target must succeed on a DC 10 Constitution saving throw or become infected with a demonic worm, at the start of each turn roll  saving throw and on success the worm is ejected on the floor and dies. An infected creature takes 10 (3d6) necrotic damage at the start of each of its turns until the worm is removed.  If the creature reaches 0 HP through necrotic damage of the worm, they do not die, they are instead corrupted.
    • Affects of Worm Infest if Successful
      • AC: The flesh of corrupted creatures becomes tougher and more resilient. Add +4 to the natural armor bonus of the base creature if it is Large or smaller, if it is Huge or larger, add +8.
      • Damage: The corrupted creature's claws lengthen, teeth multiply, and muscles harden. The damage die used when the creature deals damage with natural attacks increases by one die type, so that 1d6 becomes 1d8, 1d8 becomes 2d6, and so on, as if the creature were one size larger.
      • Special Attacks: A corrupted creature retains all the special attacks of the base creature.
      • Special Qualities: A corrupted creature retains all the special qualities of the base creature and also gains darkvision with a range of 60 feet plus acid immunity. It also gains the special qualities described below.
      • Damage Reduction (Ex): Corrupted creatures gain damage reduction according to their Hit Dice.
        • see table at bottom
      • If the base creature already has damage reduction, use the better value.
      • Disruptive Attack: The corrupt creature deals additional vile damage when it touches uncorrupted, living, corporeal non-outsiders. The amount of vile damage dealt is equal to half of the creature's Hit Dice (maximum 20 points of damage). For example, a 14-HD corrupted frost worm deals an additional 7 points of vile damage with its bite attack.
      • Enhanced Power: The save DCs of any and all of the corrupt creature's special attacks increase by +4.
      • Fast Healing: Each round, a corrupted creature heals damage equal to half of its Hit Dice (maximum of 10 points healed). If the base creature already has fast healing, use the better value.
      • Abilities: Modify the base creature as follows: Str +4, Dex -2, Con +4, Int +0, Wis -2, Cha -2.
      • Climate/Terrain: Any land and underground.
      • Challenge Rating: Up to 3 HD, same as base creature +1, 4 HD to 7 HD, same as the base creature +2, 8+ HD, same as the base creature +3.
      • Alignment: Always evil.

        Hit Dice	Damage Reduction
        1-3	-
        4-7	5/+1
        8-11	5/+2
        12+	10/+3

• Absorption: when a worm fully corrupts a creature they are compelled to return to Kyuss.  They must do so by moving their maximum movement in the straightest line possible to get within 5ft. During the absorption process neither Kyuss or the creature can take any other actions, the creature at the end of Kyuss' turn is then sucked into the mass of Kyuss and stored in a dimensional pocket where Kyuss contains their demonic energy for his own growth.  If he absorbs enough creatures he grows physically one size (DM Discretion).
• Corrupting Gaze (Recharge 6): The demon targets one creature it can see within 30 feet of it. The target must succeed on a DC 18 Wisdom saving throw or be frightened for 1 minute. The frightened target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

If Kyuss takes 30 damage or more on a single turn, he must succeed on a DC 18 Constitution saving throw at the end of that turn or regurgitate some (1d4) or all of his absorbed creatures, which fall prone in a space within 10 feet of Kyuss. If Kyuss dies, all absorbed creatures are ejected from his body.

Spellcasting (Psionics). Kyuss casts one of the following spells, requiring no spell components and using Wisdom as the spellcasting ability (spell save DC 16):

At will: levitate

1/day each: confusion, feeblemind, telekinesis

• Detect: The demon makes a Wisdom (Perception) check.
• Tendril Swipe: The demon makes one tendril strike.
• Summon Minions (Costs 2 Actions): The demon summons 2d4 worm-infested minions that appear in unoccupied spaces within 60 feet of it and act on its own initiative.