Regeneration. The troll regains 10 hit points at the start of its turn. If the troll takes acid or fire damage, it regains only 5 hit points at the start of its next turn. The troll dies only if it is hit by an attack that deals 10 or more acid or fire damage while the troll has 0 hit points.
Multiattack. The troll makes one Bite attack and four Claw attacks.
Bite. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit:10 (1d8 + 6) piercing damage plus 5 (1d10) poison damage.
Claws. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit:16 (3d6 + 6) slashing damage.
Whirlwind of Claws (Recharge 5–6). Each creature within 10 feet of the troll must make a DC 19 Dexterity saving throw, taking 44 (8d10) slashing damage on a failed save, or half as much damage on a successful one.
Trolls that are nearly obliterated but survive and regenerate from mere scraps of flesh can display bizarre features. Radically transformed trolls like the rot trolls, spirit trolls, and venom trolls that follow are especially likely to arise when trolls regenerate in the presence of magical emanations, planar energy, disease, or death on a vast scale, or if their bodies were damaged by elemental forces. These unusual forms can also be produced and shaped by the ritual magic of evil…