Black Sap

Contagion. Any creature that touches Black Sap, hits it with a melee attack, or is hit with a melee attack from Black Sap, is afflicted with a disease of Black Sap’s choice from any of the ones described below. At the end of each of the target’s turns, it must make a Constitution saving throw (DC 15). After failing three of these saving throws, the disease’s effects last for seven days, and the creature stops making these saves. After succeeding on three of these saving throws, the creature recovers from the disease. Since the spell induces a natural disease in its target, any effect that removes a disease or otherwise ameliorates a disease’s effects apply to it:

• Blinding Sickness. Pain grips the creature’s mind, and its eyes turn milky white. The creature has disadvantage on Wisdom checks and Wisdom saving throws and is blinded (a blinded creature can’t see and automatically fails any ability check that requires sight; attack rolls against the creature have advantage, and the creature’s attack rolls have disadvantage).
• Filth Fever. A raging fever sweeps through the creature’s body. The creature has disadvantage on Strength checks, Strength saving throws, and attack rolls that use Strength.
• Flesh Rot. The creature’s flesh decays. The creature has disadvantage on Charisma checks and vulnerability to all damage.
• Mindfire. The creature’s mind becomes feverish. The creature has disadvantage on Intelligence checks and Intelligence saving throws, and the creature behaves as if under the effects of the confusion spell during combat (an affected creature can’t take reactions and must roll a d10 at the start of each of its turns to determine its behavior for that turn: 1) the creature uses all its movement to move in a random direction. To determine the direction, roll a d8 and assign a direction to each die face. The creature doesn’t take an action this turn; 2-6) The creature doesn’t move or take actions this turn; 7-8) The creature uses its action to make a melee attack against a randomly determined creature within its reach. If there is no creature within its reach, the creature does nothing this turn; 9-10) The creature can act and move normally
• Seizure. The creature is overcome with shaking. The creature has disadvantage on Dexterity checks, Dexterity saving throws, and attack rolls that use Dexterity.
• Slimy Doom. The creature begins to bleed uncontrollably. The creature has disadvantage on Constitution checks and Constitution saving throws.In addition, whenever the creature takes damage, it is stunned until the end of its next turn.

Multiattack. The treant makes two slam attacks.

Slam. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 16 (3d6 + 6) bludgeoning damage.

Rock. Ranged Weapon Attack: +10 to hit, range 60/180 ft., one target. Hit: 28 (4d10 + 6) bludgeoning damage.

Cloudkill (2/day). 5th-level conjuration, range: 120 ft., concentration: up to 10 min. You create a 20-foot-radius sphere of poisonous, yellow-green fog centered on a point you choose within range. The fog spreads around corners. It lasts for the duration, or until a strong wind disperses the fog, or until your concentration is broken. When a creature enters the spell’s area for the first time on a turn or starts its turn there, that creature must make a DC 15 Constitution saving throw. The creature takes 22 (5d8) poison damage on a failed save, or half as much on a successful one. Creatures are affected even if they hold their breath or don’t need to breathe. The fog moves 10 feet away from you at the start of each of your turns, rolling along the surface of the ground. The vapors, being heavier than air, sink to the lowest level of the land, even pouring down openings.

Blight (3/day). 4th-level necromancy, range 30 ft. Necromantic energy washes over a creature of your choice that you can see within range, draining moisture and vitality from it. The target makes a DC 15 Constitution saving throw, taking 36 (8d8) necrotic damage on a failed save, or half as much on a successful one. This spell has no effect on undead or constructs.