Living a life in the Underdark grants every Drow excellent darkvision up to 120 feet. While in sunlight, the Drider has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

You have long venomous fangs that can strike and debilitate prey. You may use your action to Bite dealing 1d4+ your Strength modifier. You are proficient with this attack. When it lands you may choose to inject a dose of poison forcing the target to make a DC 12 Constitution saving throw. If the target succeeds the save nothing happens, if they fail they take 2d4 poison damage. This damage increases to 2d6 at lvl 11 and 2d8 at lvl 16. You may apply this poison a number of times equal to your proficiency and regain all charges after a long rest.

Your Elven blood is no more. You are now a Monstrosity and gain +1 Con and +2 Dex. You are immune to poison and the poisoned condition.

The Drider ignores movement restrictions caused by webbing. The Drider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

As an action you may create 10 feet of webbing that acts as rope with the same tensile strength and due to its stickiness any creature that has been tied up by the web makes its strength saving throw with disadvantage. You may create webbing up to 20 feet times your proficiency bonus. You need not make all the web at once. If you wish to make a net-like web it will be 1 foot in diameter for every 2 feet of web used. For example, using 40 feet of web will make a web that covers a 20 foot cube. For every 10 feet of web you create it takes 1 minutes to spin, therefor a 20 foot cube of web takes 2 minutes to create. You may use this trait as many times as you like however all webbing expended is regained upon finishing a long rest. Any webs created fall apart after 24 hours.