Aura of Sickness (Concentration). While the Dragon is not incapacitated, creatures that start their turn within 5ft of the dragon must make a DC 18 CON save or be poisoned until the start of their next turn.
Dragon Rage. If the dragon begins its turn with less than 179hp it gains resistance to all non-magical piercing, bludgeoning, and slashing damage.
Multiattack. The dragon makes 4 attacks. One with its bite and 3 with its claws.
Bite. Melee Weapon Attack: +11 to hit, Reach 10ft.
Hit. 20 (2d10+7) piercing damage plus 9 (2d8) Poison damage.
Claw. Melee Weapon Attack: +11 to hit, Reach 5 ft.
Hit: 16 (2d8+7) slashing damage.
Poison Breath (Recharge 5-6). The dragon exhales poisonous gas in a 40-foot Cone. Each creature in that area must make a DC 18 CON Save, taking 39 (11d6) Poison damage on a failed save, or half as much damage on a successful one.
For every 5 below the save, failing creatures incur a random condition: Blindness, Poisoned, Incapacitated, or fall Prone at the end of every turn. This condition lasts for 1 minute or until they make the save at the end of their turn.
Ray of Sickness. Level 4 Spell, Range 70ft.
A ray of energy lashes out toward a creature within range. Target takes 23 (4d8) Poison damage and must make a DC 16 CON Save or be poisoned until the end of their next turn.
Beastmode.The creature has as many Legendary Actions as it has consumed Legendary Resistances. One action = One attack. Full Round Action = 2 Actions.
Legendary Resistance (OOOOOOOOO/day). When the creature fails a saving throw, it may choose to succeed instead, expending a Resistance point and adding to its Legendary Action pool.
Change Shape. The dragon can transform into any creature that is Medium or Small, while retaining its game statistics. This transformation ends if the dragon is reduced to 0 hit points or uses its action to end it.
3x Engulf. The Dragon swallows a creature it is grappling. To keep an unwilling creature down, the Dragon must make a concentration check when taking damage.
While engulfed, creatures are restrained and blinded, take 46 (7d12) Psychic and Acid damage at the start of each turn (DC 17 CON for half), and take half the damage dealt to the Dragon from outside.
Bite. Natural Weapon. +11 to hit.
Hit. 52 (7d12+6) Piercing and Poison damage, and is Grappled (DC 19).The dragon then makes 3x Claw attacks.
3x Claw Multiattack Natural Weapon. +11 to hit.
Hit. 17 (3d6+6) Slashing damage.
4x Tail. Natural Weapon. +11 to hit, Reach 15ft.
Hit. 60 (12d8+6) Bludgeoning damage, and the target must make a STR save vs half the damage or be knocked prone. Failure by 5 or more and they are stunned until the end of their next turn.
Nightmare Breath (Recharge 5–6). The dragon exhales a cloud of spores in a 60ft cone. Each creature in that area must make a DC 17 WIS Save. On a failed save, the creature takes 39 (6d12) Psychic damage, and it is Charmed by the dragon for 1 minute. (Half on Success). A charmed creature can repeat the save at the end of each of its turns, ending the effect on success.
4x Commanding Spores. The dragon releases spores around a creature within 30ft that it can see. The target must succeed on a DC 17 WIS save or use its reaction to make a melee weapon attack against a random creature within reach.
If no creatures are within reach, or the target can’t take a reaction, it takes 7 (1d12) Psychic damage.
Creatures charmed by the dragon have disadvantage.
3x Spore Salvo. (Recharge 4). The dragon releases poisonous spores around a creature within 30ft of it that it can see. The target must succeed on a DC 17 CON Save or take 21 (6d6) Poison damage and become Poisoned for 1 minute. The poisoned creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Lightning Absorption. Whenever the shambling mound is subjected to lightning damage, it takes no damage and regains a number of hit points equal to the lightning damage dealt.
Multiattack. The shambling mound makes 3slam attacks. If both attacks hit a Medium or smaller target, the target is grappled (Escape DC 14), and the shambling mound uses its Engulf on it.
Slam. Weapon Attack, +5 to hit.
Hit. 8 (1d8+3) bludgeoning damage.
Engulf. The shambling mound engulfs a Medium or smaller creature grappled by it. The engulfed target is Blinded, Restrained, and unable to breathe, and it must succeed on a DC 14 CON Save at the start of each of the mound's turns or take 8 (1d8+3) bludgeoning damage. If the mound moves, the engulfed target moves with it. The mound can have only one creature engulfed at a time.
Vine Whip. Weapon Attack, +5 to hit, Range 30ft.
Hit. 19 (3d8+5) Slashing damage.