Regeneration. The guardian regains 5 hit points at the start of its turn. If the guardian takes fire damage, this trait doesn't function at the start of the guardian's next turn. The guardian dies only if it starts its turn with 0 hit points and doesn't regenerate. 

Multi attack: the forest guardian can make two slam attacks

Slam. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 16 (3d8 + 4) bludgeoning damage.

Grasping Vines (Recharge 6). At the guardian's command, a 20 foot circle within 60 feet of the guardian is entangled with thorny vines, which counts as difficult terrain. Characters within the radius must make a DC 13 Strength saving throw or take 3d6 piercing damage and be restrained until the end of the guardian's next turn.