Fey Ancestry. The drow has advantage on saving throws against being charmed, and magic can't put the drow to sleep.
Innate Spellcasting. The drow's spellcasting ability is Charisma (spell save DC 12). It can innately cast the following spells, requiring no material components:
At will: dancing lights
1/day each: darkness, faerie fire, levitate (self only)
Sunlight Sensitivity. While in sunlight, the drow has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.
Multiattack. The drow makes two shortsword attacks.
Shortsword. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) piercing damage plus 10 (3d6) poison damage.
Hand Crossbow. Ranged Weapon Attack: +7 to hit, range 30/120 ft., one target. Hit: 7 (1d6 + 4) piercing damage, and the target must succeed on a DC 13 Constitution saving throw or be poisoned for 1 hour. If the saving throw fails by 5 or more, the target is also unconscious while poisoned in this way. The target wakes up if it takes damage or if another creature takes an action to shake it awake.
Keen Hearing and Smell. The hound has advantage on Wisdom (Perception) checks that rely on hearing or smell
Pack Tactics. The hound has advantage on an attack roll against a creature if at least one of the hound's allies is within 5 feet of the creature and the ally isn't incapacitated.
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) piercing damage plus 7 (2d6) fire damage.
Fire Breath (Recharge 5–6). The hound exhales fire in a 15-foot cone. Each creature in that area must make a DC 12 Dexterity saving throw, taking 21 (6d6) fire damage on a failed save, or half as much damage on a successful one.