Greater Yuan-ti Form

You have unlocked more of your serpentine heritage. You gain the following benefits:

• Increase your Intelligence or Charisma score by 1, to a maximum of 20.
• You can use an action to polymorph into either a Medium giant poisonous snake, or into a Large constrictor snake, or back into your true form. Your statistics, other than your size, are the same in each form. Any equipment you are wearing or carrying isn’t transformed. If you die, you stay in your current form.
• You gain a bite attack as a natural weapon, which you can use to make unarmed strikes. If you hit with it, you deal piercing damage equal to 1d4 + either your Strength or Dexterity modifier, instead of the bludgeoning damage normal for an unarmed strike. When you hit with a bite attack, you deal 1d6 additional poison damage to the target.