Who is Cowlquape Pentephraxis from The Last of the Sky Pirates and what is their importance?

Cowlquape Pentephraxis is a Librarian Academic. He has been imprisoned by Orbix Xaxis in the Tower of Night for many years. Friends with Xanth, he tells the boys stories of his adventures in the Deepwoods which leads Xanth to go to Lake Landing as a spy so he can experience some of the wonders himself. When Twig mentions Cowlquape who he thinks is dead, Rook quickly corrects Twig's error, and they decide to rescue Cowlquape. Twig and his crew of banderbears attack the Tower of Night, distracting the Guardians of Night, while Rook sneaks into the dungeons on the other side of the tower and frees Cowlquape.