David Hyde Pierce

David Hyde Pierce is a guest star on The Simpsons who played Sideshow Bob's brother Cecil. He first appeared in Season 8's Brother from Another Series and ten years later in Funeral for a Fiend. He is best known for playing Fraiser Crane's brother Niles in Fraiser. Sideshow Bob is voiced by Kelsey Grammer who plays Fraiser Crane in Fraiser who is the brother of Niles. John Mahoney who played Martin Crane who is the father of both Fraiser and Niles would later play the the father of Bob and Cecil.