Bob Newhart reprises his Emmy-winning guest role as Professor Proton/Arthur Jeffries, a former science TV show host turned children's party entertainer, on Thursday's episode of "The Big Bang Theory" (8 p.m., CBS/2). Here are five other notable TV guest appearances that Newhart, now 84, has done in his long TV career:
THE ALFRED HITCHCOCK HOUR (1963) In an episode of the mystery anthology titled "How to Get Rid of Your Wife," Newhart (then best known as a stand-up comic) played a henpecked husband who devises a plan to eliminate his spouse.
MURPHY BROWN (1994) Newhart showed up as his Bob Hartley character from "The Bob Newhart Show" (which had been gone from the air since 1978). His former receptionist (Marcia Wallace) was now working as a secretary for Murphy (Candice Bergen) and Dr. Hartley comes to Washington, D.C., to persuade her to return to Chicago.
ER (2003) In an Emmy-nominated, three-episode arc, Newhart played a visual artist who was distraught over losing his sight.
DESPERATE HOUSEWIVES (2005) He did guest shots as Morty, the on-again/off-again boyfriend of Sophie (Lesley Ann Warren), the mother of Susan (Teri Hatcher).
NCIS (2011) In another memorable dramatic turn, Newhart played Dr. Walter Magnus, who preceded Ducky (David McCallum) as chief medical examiner and was suffering the effects of early onset Alzheimer's.