Armadillo is mentioned when Thorn thought of planning a party to celebrate Sunny's arrival. Later, Thorn told Sunny that only Six-Claws and Armadillo knew of Sunny's relationship with Thorn.
It is possible she/he is one of the SandWings that entered with Thorn when Sunny met her.
While little is known about Armadillo's personality, Thorn states that Armadillo was one of the few dragons she could trust with her deepest secrets, so that may hint that Armadillo is trustworthy and loyal to Thorn.
Trivia
An armadillo is a mammal that has a shell that it uses as a defense. They are usually found in deserts.
