Blighted Yggdrasti Elder

Cavities. The Yggdrasti has 1d4 + 4 cavities in its trunk, each large enough to hold one Medium creature, two Small creatures, or eight Tiny creatures. Creatures inside a cavity have three-quarters cover against attacks and effects originating from outside the cavity. The cavities are not connected to one another.

False Appearance. If the Yggdrasti Elder is motionless and rooted in the ground at the start of combat, it appears as a dead tree and gains advantage on its initiative roll. If a creature hasn’t observed the rooted Yggdrasti move, it must succeed on a DC 20 Intelligence (Investigation) check to recognize it as animate.

Hive Mind. The Yggdrasti Elder shares a hive mentality with other Blighted creatures, allowing them to act in unison.

Blighted Scourge. Natural weapon attacks by the Blighted Yggdrasti can infect creatures with the Blighted Scourge (DC 17 Wisdom save).

Lightning Conduit. If subjected to lightning damage, the Yggdrasti Elder takes no damage; instead, the damage is evenly divided among all creatures it is grappling. Additionally, the Yggdrasti Elder regains one use of Blight Discharge.

Unusual Nature. The Yggdrasti Elder doesn’t require air or sleep.

Multiattack. The Yggdrasti Elder makes three Root attacks and may use Blight Discharge if available.

Root. Melee Weapon Attack: +11 to hit, reach 25 ft., one target. Hit: 19 (3d8 + 6) bludgeoning damage. If the target is a creature, it is grappled (escape DC 18). The Yggdrasti Elder can grapple up to four creatures with its roots.

Branch Slam. Melee Weapon Attack: +11 to hit, reach 20 ft., one target. Hit: 27 (4d10 + 6) bludgeoning damage.

Blight Discharge (3/Day). The Yggdrasti Elder targets a creature within 120 feet with a blast of blighted energy. The target must make a DC 17 Constitution or Wisdom saving throw, taking 45 (10d8) necrotic damage on a failed save and advancing one stage in the Blighted Scourge. On a success, the target takes half damage and resists the scourge.

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

• Root Strike. The Yggdrasti Elder makes one Root attack.
• Corrupted Ground (Costs 2 Actions). The ground in a 20-foot radius within 30 feet of the Yggdrasti Elder becomes corrupted for 1 minute. This area is difficult terrain, and creatures that enter it for the first time on a turn take 11 (2d10) necrotic damage.
• Blighted Grasp (Costs 3 Actions). The Yggdrasti Elder reaches out with corrupted roots toward a creature within 30 feet. The target must succeed on a DC 17 Strength saving throw or be restrained for 1 minute. While restrained in this way, the target takes 13 (3d8) blighted energy damage at the start of each of its turns. The target can repeat the saving throw at the end of each of its turns, ending the effect on a success.