Aside from being a griffin, Jason has 3 defining attributes: He likes to draw, he is Alexander's little brother, and he's mighty shy around his classmates, the pegasus and assorted chimera.
When faced with the prospect of the year in middle school without his big brother to protect him, Jason turns to his imaginary friend - a fearless human named Robert - for guidance and gets a crash course in how to overcome his fears in order to make friends.