Regeneration. The viper tree regains 10 hit points at the start of its turn. If the viper tree takes necrotic damage, this trait doesn’t function at the start of the viper tree’s next turn. The viper tree dies only if it starts its turn with 0 hit points and doesn’t regenerate.

Wretched Stench. Any creature other than a fiend that starts its turn within 30 feet of the viper tree must succeed on a DC 16 Constitution saving throw or be poisoned for 1 minute. While poisoned in this way, the target cannot move or take actions while it retches and reels. A creature may repeat its saving throw at the end of each of its turns, ending the effect on itself with a success. Creatures that don’t need to breathe or are immune to poison automatically succeed on this saving throw.

Multiattack. The viper tree makes three attacks, but can only make one attack with its roots.

Bite. Melee Weapon Attack: +7 to hit, reach 10 ft., one creature. Hit: 8 (1d10 + 3) piercing damage plus 14 (4d6) poison damage, and the target must make a DC 16 Constitution saving throw or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Roots. Melee Weapon Attack: +7 to hit, reach 30 ft., one creature. Hit: 12 (2d8 + 3) bludgeoning damage and the target is grappled (escape DC 16). Until the grapple ends, the target is restrained and has disadvantage on Strength checks and Strength saving throws, and the viper tree can’t use its roots on another target.

Viper Blossoms. When the viper tree is subjected to slashing or fire damage, some of the serpents on its branches break off and fall to the ground. These viper blossoms use the statistics of a swarm of poisonous snakes. The swarm appears in a space within 5 feet of the viper tree and acts as an ally of the viper tree.