Colossus Vine

Plant Camouflage. The vine has advantage on Dexterity (Stealth) checks it makes in any terrain with ample obscuring plant life.

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

Tunneler. The vine can burrow through solid rock at its burrow speed and leaves a 10-foot-diameter tunnel in its wake.

Multiattack. The vine makes two melee attacks.

Hurled Stone. Ranged Weapon Attack: +16 to hit, range 200/800 ft., one target. Hit: 43 (6d10 + 10) bludgeoning damage.

Constrict. Melee Weapon Attack: +16 to hit, reach 20 ft., one creature. Hit: The target takes 31 (6d6 + 10) bludgeoning damage, and it is grappled (escape DC 24). Until this grapple ends, the target is restrained.

Whip. Melee Weapon Attack: +16 to hit, reach 50 ft., one target. Hit: 31 (6d6 + 10) slashing damage.

Deadly Bloom (1/Day). Flowers sprout from the vine and spray a cloud of noxious fumes, which spreads around corners. Each creature within 250 feet of the vine must make a DC 22 Constitution saving throw, creatures that are grappled by the vine have disadvantage on the roll. Targets that fail the save take 33 (6d10) poison damage and are poisoned for 1 hour. On a success, targets take half damage and are not poisoned. Plants are immune to this poison.

The vine 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 vine regains spent legendary actions at the start of his turn.

Move. The vine moves up to its speed.

Snare. The vine make a whip attack against. On a hit, the target is additionally pulled 30 feet closer to the vine, and it is grappled (escape DC 24). Until this grapple ends, the target is restrained.

Tighten (Costs 2 Actions). The vine tightens its grip. Each creature grappled by the vine takes 21 (6d6) bludgeoning damage.