Actions

• Multiattack.The greatwyrm can use frightful presence and make one Bite attack and two Claw attacks.

• Bite.Melee Weapon Attack:+18 to hit, reach 15 ft., one target.Hit:21 (2d10 + 10) 2d10+10 piercing damage plus 13 (2d12) 2d12 force damage.
• Claw.Melee Weapon Attack:+18 to hit, reach 10 ft., one target.Hit:19 (2d8 + 10) 2d8+10 slashing damage. If the target is a Huge or smaller creature, it is grappled(escape DC 20) and is restrained until this grapple ends. The greatwyrm can have only one creature grappled this way at a time.
• Tail.Melee Weapon Attack:+18 to hit, reach 20 ft., one target.Hit:19 (2d8 + 10) [roll2d8+10] bludgeoning damage. If the target is a creature, it must succeed on a DC 26 Strength saving throw or be knocked prone
• .Breath Weapon (Recharge 5–6).The greatwyrm exhales a blast of energy in a 300-foot cone. Each creature in that area must make a DC 26 Dexterity saving throw.On a failed save, the creature takes 78 (12d12) 12d12 damage of a type poison(green). On a successful save, the creature takes half as much damage.
• Frightful Presence: Each creature of the dragon's choice that is within 120 feet of the Dragon and aware of it must succeed on a DC 16 Wisdom saving throw or become Frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, Ending the Effect on itself on a success. If a creature's saving throw is successful or the Effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.

Legendary Actions

The greatwyrm can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of anothercreature’s turn. The greatwyrm regains spent legendary actions at the start of its turn.

• Attack.The greatwyrm makes one Claw or Tail attack.
• Wing Attack (Costs 2 Actions).The greatwyrm beats its wings. Each creature within 30 feet of it must succeed on a DC 26 Dexterity saving throw or take 17 (2d6 +10) bludgeoning damage and be knockedprone. The greatwyrm can thenfly up to half itsflying speed.
• Arcane Spear (Costs 3 Actions).The greatwyrm creates four spears of magical force. Each spear hits a creature of the greatwyrm’s choice it can see within 120 feetof it, dealing 12 (1d8 + 8) force damage to its target, then disappears
• Cast spell: can cast a spell
• Chromatic Flare (Costs 2 Actions).The greatwyrmflares with elemental energy. Each creature in a 60-foot-radius sphere centered on the greatwyrm must succeed on a DC 26 Dexterity saving throw or take 22 (5d8) poison (green).

• Mythic Actions:If the greatwyrm’s Chromatic Awakening trait has activated in the last hour, it can use the options below as legendary actions.
• Bite.The greatwyrm makes one Bite attack.

Lair Actions

• Grasping roots and vines erupt in a 20-foot radius centered on a point on the ground that the dragon can see within 120 feet of it. That area becomes difficult terrain, and each creature there must succeed on a DC 15 Strength saving throw or be restrained by the roots and vines. A creature can be freed if it or another creature takes an action to make a DC 15 Strength check and succeeds. The roots and vines wilt away when the dragon uses this lair action again or when the dragon dies.
• A wall of tangled brush bristling with thorns springs into existence on a solid surface within 120 feet of the dragon. The wall is up to 60 feet long, 10 feet high, and 5 feet thick, and it blocks line of sight. When the wall appears, each creature in its area must make a DC 15 Dexterity saving throw. A creature that fails the save takes 18 (4d8) piercing damage and is pushed 5 feet out of the wall’s space, appearing on whichever side of the wall it wants. A creature can move through the wall, albeit slowly and painfully. For every 1 foot a creature travels through the wall, it must spend 4 feet of movement. Furthermore, a creature in the wall’s space must make a DC 15 Dexterity saving throw once each round it’s in contact with the wall, taking 18 (4d8) piercing damage on a failed save, or half as much damage on a successful one. Each 10-foot section of wall has AC 5, 15 hit points, vulnerability to fire damage, resistance to bludgeoning and piercing damage, and immunity to psychic damage. The wall sinks back into the ground when the dragon uses this lair action again or when the dragon dies.
• Magical fog billows around one creature the dragon can see within 120 feet of it. The creature must succeed on a DC 15 Wisdom saving throw or be charmed by the dragon until initiative count 20 on the next round.

Regional Effects

Pass Without a Trace: Within 1 mile of his lair, Varnax leaves no physical evidence of his passage unless he wishes to. Tracking him is impossible except through magical means. He ignores movement impediments and damage from plants in this area that aren’t magical or creatures. Plants remove themselves from his path.    

• Rodent Eyes and Ears: Rodents and birds within 1 mile of Varnax’s lair serve as his eyes and ears. Deer and large game are strangely absent, hinting at the presence of an unnaturally hungry predator. If Varnax dies, the rodents and birds lose their supernatural link to him