Cursed Treant Lord

Siege Monster. The Cursed Treant Lord deals double damage to objects and structures.

False Appearance. While the Cursed Treant Lord remains motionless, it is indistinguishable from an ordinary, dead tree.

Magic Resistance. The Cursed Treant Lord has advantage on saving throws against spells and other magical effects.

Magic Immunity. The Cursed Treant Lord is immune to any spell or effect that would alter its form.

Multiattack. The Cursed Treant Lord makes three attacks: two with its Slam and one with its Grasping Roots.

Slam. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 32 (4d10 + 7) bludgeoning damage.

Grasping Roots. The Cursed Treant Lord targets a creature within 60 feet that it can see. The target must succeed on a DC 18 Strength saving throw or become restrained by grasping roots and take 22 (4d8 + 4) bludgeoning 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.

Curse of the Cursed Treant (Recharge 6). The Cursed Treant Lord casts a malevolent curse upon a creature it can see within 120 feet. The target must succeed on a DC 18 Wisdom saving throw or be afflicted by the Curse of the Cursed Treant. While cursed, the target has disadvantage on attack rolls, saving throws, and ability checks. The curse lasts for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the curse on a success.

Entangling Vines (Recharge 5-6). The Cursed Treant Lord summons thick vines that cover a 20-foot square on the ground. The area becomes difficult terrain. Each creature that starts its turn in the area must succeed on a DC 18 Strength saving throw or be restrained by the entangling vines. A creature can use its action to make a DC 18 Strength check, ending the effect on a success.