Ancient Forest Dragon

Amphibious. The dragon can breathe air and water.

Damage Threshold. 21

Legendary Resistance (3/Day). If the dragon fails a saving throw, it can choose to succeed instead.

False Appearance. While the forest dragon remains motionless, it is indistinguishable from the rest of the forest.

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

Multiattack. The dragon can use its Frightful Presence. It then makes three attacks: one with its Constrict and two with its claws.

Constrict. Melee Weapon Attack: +11 to hit, reach 20 ft., one creature. Hit: The target takes 15 (2d6 + 8) bludgeoning damage, and it is grappled (escape DC 22). Until this grapple ends, the target is restrained, and it takes 28 (8d6) poison damage at the start of each of its turns. The dragon can constrict only one target at a time.

Claw. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) slashing damage.

Tail. Melee Weapon Attack: +14 to hit, reach 20 ft., one target. Hit: 17 (2d8 + 8) bludgeoning damage.

Frightful Presence. Each creature of the dragon's choice that is within 120 feet of the dragon and aware of it must succeed on a DC 19 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.

Barrage Breath (Recharge 5–6). The dragon exhales sharp wooden javelins in a 60-foot cone. Each creature in that area must make a DC 19 Constitution saving throw, taking 90 (20d8) piercing damage on a failed save, or half as much damage on a successful one.

Tree Devour. The dragon consumes a nearby tree to recharge it's Barrage Breath if it failed a recharge roll to start this turn.

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

Grasping Roots. The dragon casts the entangle spell

Constrict. The dragon makes a constrict attack.

Aura of Briars (Costs 2 Actions). A wall of tangled brush bristling with thorns springs into existence surrounding the dragon up to 30 foot radius until the start of its next turn. Each creature in its area must make a DC 15 Dexterity saving throw. A creature that fails the save takes 27 (6d8) piercing damage and is grappled. On a success the creature takes half damage and is not grappled.