On what date did Fox air an episode featuring Robert Underdunk Terwilliger Jr., Ph.D.?
Krusty Gets Busted:  It originally aired on the Fox network in the United States on April 29, 1990. Sideshow Bob: Robert Underdunk Terwilliger Jr., Ph.D., better known as Sideshow Bob, is a recurring character in the animated television series "The Simpsons."
April 29, 1990.