Never encountered by my group so it still lurks in the Palace of Fallen Stars.
Armour Class 17 (natural armour)
Hit Points 190 (20d8+100)
Speed 10 ft.
STR 26 (+8) DEX 19 (+4) CON 19 (+4)
INT 1 (-5) WIS 10 (+0) CHA 6 (+0)
Damage Vulnerabilities fire
Damage Resistances bludgeoning, piercing
Senses passive Perception 10
Challenge 14 (11,500 XP)
Cold Lethargy. Exposure to any cold effect slows a viper vine as a slow spell.
False Appearance. While the vine remains motionless, it is indistinguishable from a normal tree.
Multiattack. The viper vine makes four vine attacks. It may also use captivating cloud if available.
Bite. Melee Weapon Attack: +13 to hit, reach 5ft., one target.
Hit: 20 (4d6+8) piercing damage plus 15 (5d6) acid.
Vine. Melee Weapon Attack: +9 to hit, reach 20 ft., one target.
Hit: 12 (2d6 + 4) bludgeoning damage and the target is grappled (escape DC
Captivating Cloud (1/Day). A viper vine can emit a transparent cloud of pollen in a 60-foot spread that has the power to lull the minds of those that smell it. Once activated, the cloud persists for 1 minute unless dispersed by moderate or stronger wind. All creatures in the cloud must succeed on a DC 18 Wisdom saving throw each round or become captivated. Once a creature becomes captivated, it takes no actions save to approach the viper vine via the most direct route possible. If this path leads it into a dangerous area, such as through fire or off a cliff, that creature receives a second saving throw to end the effect before moving into peril. A victim that is attacked by the viper vine gets a new saving throw as a reaction during each of the vine’s attacks to overcome the effect.
FEED ME! The viper vine may make a bite attack against a grappled foe when first grappled, the creature tries to escape or the creature attacks the viper vine.
Large tendrils ending in tiny claws unfurl from the central stalk of this plant, which rises like a serpent ready to strike.