The devil makes three attacks: two with its claws and one with its sting.
1
2
melee
Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 8 (1d8 + 4) slashing damage.
8
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 .