Blackroot Treant

Aura of Blight. A living creature that starts its turn within 10 feet of the treant takes 7 (2d6) necrotic damage.

False Appearance. While the treant remains motionless, it is indistinguishable from a normal tree.

Innate Spellcasting. The treant's innate spellcasting ability is Wisdom (spell save DC 17). The treant can innately cast the following spells, without providing material components:

At will: darkness, detect thoughts

3/day each: blight, enervation, negative energy flood

1/day each: Abi-Dalzim's horrid wilting

Siege Monster. The treant deals double damage to objects and structures.

Multiattack. The treant makes two slam attacks.

Rotting Slam. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 17 (3d6 + 7) bludgeoning damage plus 10 (3d6) necrotic damage. If the target is a creature, it must succeed on a DC 17 Constitution saving throw or its hit point maximum is reduced by an amount equal to the necrotic damage taken. This reduction lasts until the creature finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.

Rock. Ranged Weapon Attack: +12 to hit, range 60/180 ft., one target. Hit: 29 (4d10 + 7) bludgeoning damage.

Animate Dead Trees (1/Day). The treant magically animates one or two dead trees it can see within 60 feet of it. These dead trees have the same statistics as a normal treant, except they have Intelligence and Charisma scores of 1, they can't speak, they have only the Slam action option, and have the undead type. An animated dead tree acts as an ally of the treant. The dead tree remains animate for 1 day or until it dies; until the treant dies or is more than 120 feet from the tree; or until the treant takes a bonus action to turn it back into an inanimate dead tree.