Frederick Gaylord Crane is the sole child of Frasier Crane and Lilith Sternin. He is still a young child when the series ends, but it is revealed in Frasier that he is Jewish, and lives with his mother in Boston after the divorce. Like his parents, he is an intellectual - managing to win the National Spelling Bee.
He makes several appearances in Cheers as a baby and a toddler, but has grown up a bit by his first Frasier (TV series) appearances. On Cheers he is portrayed by twin actors Christopher and Kevin Graves and by Trevor Einhorn on Frasier.