Wanyuu is a large white serpent with dark blue stripes along her body that start below her head. She has piercing blue eyes, long snake fangs, and a forked tongue divided into three tips. Long, airy feathers sprout from the top of her head, her cheeks, and the tip of her tail. They are light blue in color, her face feathers also including a darker blue streak. She also has faintly blue-tinted feathered wings coated in a gold armor, with a spike and three sapphire gems on the joint. She wears a small, silver and gold-trimmed chestplate covered in dark blue magic gems. Ice-like gems also line her back and the tip of her tail.
Despite her fearsome appearance, Wanyuu is a very kind and compassionate Destiny Guardian, with a soft and comforting voice. She often will ask questions in concern of her master's safety, but remains loyal if they so insist.
- Wanyuu is based on Awanyu, a feathered serpent who was the guardian of water in Tewa mythology. Her name is also based on its name.
- North initially described her as "a white snake with blue eyes, golden stripes, and golden wings like angel wings with light blue jewels or armor on top".