Rex Dizznee is a Level Two at Foxfire in the second book of the series which is Exile. Meanwhile, in the latest books, he and the triplets are in the middle of being a level two. This would set their ages at about twelve or thirteen. They are the subject of much controversy in the Elvin World as twins are rare and triplets are even more so. Rumors state that the triplets are a result of a bad match between Kesler (a talentless) and Juline. They are the niece and nephews of both Grady and Edaline Ruewen and Kesler’s brothers and sisters. He enjoys teasing Dex, along with Bex and Lex, implying that Dex has a crush on Sophie, and love to embarrass him in front of others, like Fitz.
The triplets are fraternal and are described as looking like two "mini-Dexes and a red-haired girl." They all share their fathers strawberry blonde hair, though it is described as wild. As well as this, Rex has a missing front tooth in the book Exile.
- Lex, Bex, and Rex are the reason Juline joined the Black Swan.
- Rex's favorite stuffed animal is Harry the Jackalope.