Your Charisma score increases by 3, your Intelligence score increases by 1, your Dexterity score increases by 2.

Purebloods mature at the same rate as humans and have lifespans similar in length to theirs. Your Half Elven Lineage Prolongs that lifespan, though not to that of full elven. You speculate that you matured at 20 years, and have remained relatively unchanged since, and could possibly live 200-300 years, should your lifestyle and survival skills prove comparable. 

Halfbloods and Drow match humans in average size and weight. Your size is Medium.

Your base walking speed is 30 feet.

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 Proficiency in Perception.

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

-You know the poison spray cantrip. You can cast animal friendship an unlimited number of times with this trait, but you can target only snakes with it. Starting at 3rd level, you can also cast suggestion with this trait. Once you cast it, you can’t do so again until you finish a long rest. Charisma is your spellcasting ability for these spells.

-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 have advantage on saving throws against spells and other magical effects.

You are immune to poison damage and the poisoned condition.

You can speak, read, and write Common, Abyssal, Draconic, Undercommon and Elvish.

Abyssal is an uncommon language spoken by most aberrations from the demonic realms. These traits are present in the dark natures of both of your bloodlines. 

Draconic is known to you from the scaled serpentine side of your blood. It is believed that all snakes are descended from Dragonkin, Drakes, Wyverns, and Wyrms. 

Undercommon is known to you through your Dark Elven Lineage. Though the Crin Dynasty thrives in the far eastern Calamity scarred wastes of Wildemount, the legacy of the Drow continues and does not forget it's deep rooted heritage of earlier empires spanning the vast Deep Roads of the Underdark. 

Elvish is fluid, with subtle intonations and intricate grammar. Elven literature is rich and varied, and their songs and poems are famous among other races. Many bards learn their language so they can add Elvish ballads to their repertoires. 

You have proficiency with One handed blades; swords, daggers, rapiers, scimitars etc, and all ranged Bow Strung weapons, long and short bows, light and heavy crossbows.

You have proficiency with Polearms; spears, halberds, glaive, lance, etc.