You can use your action to magically assume the shape of a beast unique to you and your family line. You can use this feature twice per day, you regain expended uses when you finish a long or short rest.

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

Demons age at a normal rate until a certain age, then stop physically aging and are practically immortal until killed

Demons are about the same size and build as humans. Your size is Medium.

Your base walking speed is 40 feet.

Thanks to your infernal heritage, you have superior vision in dark and dim conditions. You can see in dim light within 60 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 resistance to cold damage.

You know the thaumaturgy cantrip. When you reach 3rd level, you can cast the hellish rebuke spell as a 2nd-level 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 Common, Abyssal and Infernal.