You have proficiency in the Perception skill.

You have advantage on saving throws against being charmed, and magic can’t put you to sleep.

Elves don’t need to sleep. Instead, they meditate deeply, remaining semiconscious, for 4 hours a day. (The Common word for such meditation is “trance.”) While meditating, you can dream after a fashion; such dreams are actually mental exercises that have become reflexive through years of practice. After resting in this way, you gain the same benefit that a human does from 8 hours of sleep.

You have disadvantage on attack rolls and on Wisdom (Perception) checks that rely on sight when you, the target of your attack, or whatever you are trying to perceive is in direct sunlight.

You have proficiency with longswords, rapiers, shortswords, hand crossbows, and longbows.

You have a venomous bite you may use to make unarmed strikes. When you hit with it, the strike deals 1d4 + your Strength modifier piercing damage, plus an additional amount of poison damage equal to your proficiency bonus, instead of the bludgeoning damage normal for an unarmed strike.

While you aren’t wearing armor, your carapace gives you a base Armor Class of 13 + your Dexterity modifier.

Your Dexterity score increases by 2, and your Charisma score increases by 1.

Although elves reach physical maturity at about the same age as humans, the elven understanding of adulthood goes beyond physical growth to encompass worldly experience. An elf typically claims adulthood and an adult name around the age of 100 and can live to be 750 years old. Ordinarily this is the same for Driders, though exile from their Drow communities can lessen their lifespan greatly.

Driders are about the same size and build as centaurs. Your size is Large.

Accustomed to the depths of the Underdark, you have superior vision in dark and dim conditions. You can see in dim light within 120 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of gray.

You have a climb speed equal to your walk speed, and can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check. You also ignore any movement restrictions caused by webbing.

You know the dancing lights cantrip. When you reach 3rd level, you can cast the faerie fire spell once with this trait and regain the ability to do so when you finish a long rest. When you reach 5th level, you can cast the darkness spell once with this trait and regain the ability to do so when you finish a long rest. Charisma is your spellcasting ability for these spells.

You can speak, read, and write Elvish and Undercommon.