Ry-Gaul is a human Jedi Master introduced in Jude Watson's Jedi Quest: The Way of the Apprentice (Scholastic, 2002), where he is one of four Masters fielded on the Radnor evacuation alongside Obi-Wan Kenobi, Siri Tachi and Soara Antana. His padawan is Tru Veld.
Watson uses him as the series' study in stillness — a Master who says almost nothing, tracks everything, and is used by the books to make a point about a training method that is not Obi-Wan's and not Siri's. He is Legends only, and he is the sort of character an encyclopedia exists for: real, published, catalogued, and unlikely ever to appear again.
Catalogue entry. This figure has a verified record here rather than a full write-up — the encyclopedia labels its own depth instead of padding it.