Corrupted Behemoth Stag

Burning Soul. The Corrupted Behemoth is resistant to fire damage.

Mindless Chaos. The Corrupted Behemoth is immune to the frightened condition and charm effects.

Charge. If the Corrupted Behemoth Stag attacks a creature with Piercing Antlers after it moves 10 feet in a straight line, it can attempt to knock that creature prone. The target must make a DC 17 Strength saving throw or be knocked prone. 

Piercing Antlers. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) bludgeoning damage.

Big Steppy. Melee Weapon Attack: +10 to hit, reach 5 ft., one prone creature. Hit: 26 (4d8 + 8) bludgeoning damage.

Thicket Antlers. As a reaction, the corrupted Behemoth Stag may attempt to block damage from an attack or spell, halving the damage taken. 

The Corrupted Behemoth Stag has 3 Legendary Actions that renew on its turn. It may take a legendary action after another creature's turn.

Lancing Thorns. 3 Legendary Actions. The Corrupted Behemoth Stag's tail surges forward in a 60 foot cone. All creatures in range must make a DC 17 Dexterity saving throw. On a failure, each creature takes 15 (2d6+8) piercing damage, and half on a successful save.

Call of the Wild. 2 Legendary Actions. The Corrupted Behemoth Stag lets out a shrill cry. All creatures within 100 feet of it must make a DC 17 Wisdom saving throw. On a failure, each creature must move its speed toward the Corrupted Behemoth Stag.

Nimble Escape. 1 Legendary Action. The Corrupted Behemoth Stag may disengage and move half of its movement speed.