Robert Terwilliger Sr.

Robert Terwilliger Sr. is the father of Sideshow Bob and Cecil Terwilliger. He is also the father-in-law of Francesca Terwilliger and the grand father of Gino Terwilliger. He is married to Dame Judith Underdunk. He is voiced by John Mahoney who played Kelsey Grammar and David Hyde Pierce's father in "Frasier".