Master Grosbeak was a male Copper Islander, and a member of Topabaw's spy network in Rajmuat. When Topabaw believed he had successfully recruited Alianne of Pirate's Swoop, he told her to report her findings to Master Grosbeak.
Grosbeak was quick to assume that Aly was making fun of him when she called him "my lord", and yelled at her. Aly played the simple-minded maiden, but also left a darking in Grosbeak's office.
Grosbeak is a minor character who only appears in Trickster's Queen.