The drider’s innate spellcasting ability is Wisdom (spell save DC 13). The drider can innately cast the following spells, requiring no material components:
Fey Ancestry. The drider has advantage on saving throws against being Charmed, and magic can’t put the drider to sleep.
Spider Climb. The drider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Sunlight Sensitivity. While in sunlight, the drider has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.
Web Walker. The drider ignores movement restrictions caused by webbing.
Multiattack. The drider makes three attacks, either with its longsword or its longbow. It can replace one of those attacks with a bite attack.
Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 2 1d4 piercing damage plus 9 2d8 poison damage.
Longsword. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 1d8+3 slashing damage, or 8 1d10+3 slashing damage if used with two hands.
Longbow. Ranged Weapon Attack: +6 to hit, range 150/600 ft., one target. Hit: 7 1d8+3 piercing damage plus 4 1d8 poison damage.