Ashen Troll

Keen Smell. The troll has advantage on Wisdom (Perception) checks that rely on smell.

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

Unstable Form. Attacks and creatures alike seem to glide through this creature.

Ash Rush. If the floor between the Ashen and the target is covered in a layer of ash it can pick up ash in its charge to add 1 damage per foot of travel.

Multiattack. The troll makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) piercing damage plus (2d6) fire damage.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage plus (2d6) fire damage.

Ash Reinforcement. The Ashen Troll uses a 5ft section of ash beneath it to sheath its body in a protective layer. Adds 10 temporary HP