Lemure

Devil's Sight. Magical darkness doesn't impede the lemure's darkvision.

Devilish Resilience. The devil is resistant to cold damage. In addition, it is immune to fire damage and poison damage and to the poisoned condition.

Hellish Rejuvenation. Unlike other outsiders, a lemure that dies in its home plane of the Hells is restored in a new body in 1d10 days, regaining all its HP and becoming active again. The new body appears in the Hells within 1 mile of where it was slain. Only sprinkling holy water on the lemure's remains can prevent this trait from functioning.

Fist. _Melee Weapon Attack:_ +4 to hit, reach 5 ft., one target. _Hit:_ 4 (1d4+2) bludgeoning damage plus 2 (1d4) fire damage.

Rippling Heat (1/Day). The lemure exudes an aura of extreme heat for 1 minute. Each creature that starts its turn within 15 feet of the lemure and that isn't a devil must succeed on a DC 11 CON save or be weakened until the start of its next turn. A weakened creature has disadvantage on all attack rolls, and it deals only half damage with weapon attacks that use Strength. A creature that fails this save by 5 or more suffers one level of exhaustion. A creature that has suffered a level of exhaustion from this lemure's Rippling Heat can't suffer another level from this lemure's Rippling Heat for 24 hours.