Simon Riley "Ghost" Avatar.

Navi Physicist:

Body: Highly developed and athletic musculature, bones reinforced with natural carbon fiber, and a long tail that helps them with balance
Skin: Smooth, dark blue or cyan in color, with darker stripes and luminescent white spots that glow in the dark
Face: Feline features, such as a flat, forked nose, pointed ears, and large golden eyes
Hair: Dark, often braided, forming a long braid called tswin/Kuru, which is a nerve extension they use to connect with other creatures and the environment. It is not human braided hair, but a vital part of their anatomy, where they share connections and bonds.
Height: 3 meters.

The difference between Ghost's Avatar body and the Navi's can be seen in their hands. The Navi's have 4 fingers on each hand and foot, while the Avatars maintain their 5 fingers on each hand and foot.
Their eyes are slightly smaller than normal Navi's.

Ghost's personality is curious, rational, and humorous, even prone to dark jokes. He's a man who initially sees things differently, but upon discovering the afterlife, his thoughts are transformed into something entirely new. He seeks to learn, but also to fulfill his missions; he is always resolute.