Sources
CR
Type
Size
Alignment
Movement

Bone Devil

Large Fiend (devil), Lawful Evil

Armor Class 19 (natural armor)
Hit Points 142 (15d10 + 60)
Speed 40 ft., fly 40 ft.
STR
18
+4
DEX
16
+3
CON
18
+4
INT
13
+1
WIS
14
+2
CHA
16
+3
Saving Throws INT +5, WIS +6, CHA +7
Skills Deception +7, Insight +6
Damage Resistances cold; bludgeoning, piercing, slashing, from nonmagical attacks that aren't silvered
Damage Immunities fire, poison
Condition Immunities Poisoned
Senses darkvision 120 ft., passive Perception 12
Languages Infernal, telepathy 120 ft.
Challenge 9 (5,000 XP)

Traits

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

Magic Resistance. The devil has advantage on saving throws against spells and other magical effects.

Actions

Multiattack. The devil makes three attacks: two with its claws and one with its sting.

Claw. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit:8 (1d8 + 4) slashing damage.

Sting. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit:13 (2d8 + 4) piercing damage plus 17 (5d6) poison damage, and the target must succeed on a DC 14 Constitution saving throw or become poisoned 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.

Lore

Devils personify tyranny, with a totalitarian society dedicated to the domination of mortal life. The shadow of the Nine Hells of Baator extends far across the multiverse, and Asmodeus, the dark lord of Nessus, strives to subjugate the cosmos to satisfy his thirst for power. To do so, he must continually expand his infernal armies, sending his servants to the mortal realm to corrupt the souls from which new devils are spawned.