Do you know who Norm Peterson's wife was on the hit sitcom "Cheers?"
Although she was the butt of many of Norm's jokes, his wife Vera was never seen during the show's 11-year run. The most audiences ever saw of her was when she took a pie to the face on a Thanksgiving episode.
Do you know what famous actor was the voice of the never-seen millionaire who owned the mansion Magnum P.I. lived in?
It was Orson Wells, best known for writing, directing and starring in "Citizen Kane," ranked by A.F.I. as the greatest American film ever made.
But in the final episode, it was suggested that the butler, Higgins, played by John Hillerman, was in fact the reclusive millionaire.
Although he eventually married his brother's housekeeper, Daphne (Jane Leeves), do you know who Niles' first wife was on the show "Frasier?"
She was never seen or heard, but Maris was a constant source of laughs for the show. She was apparently lizard-like in appearance and so thin she once sprained her wrist from putting too much dip on a chip.
Do you know who Robin Williams' extraterrestrial boss was on "Mork and Mindy?"
At the end of each episode, Mork reported back to his unseen Orkan boss, Orson.
Do you know who the unseen character Diane was on the show "Twin Peaks?"
It was never fully explained, but she seemed to be Agent Cooper's secretary, whom he frequently gave notes and everyday observations to on his Dictaphone. One such observance: "Diane, last night I dreamed I was eating a large, tasteless gumdrop, and awoke to discover I was chewing on one of my foam disposable earplugs. Perhaps I should consider moderating my nighttime coffee consumption."
Do you know who the unseen characters are on the show "Scrubs?"
Dr. Bob Kelso often speaks of his family, but they are never seen on screen. Apparently, his wife, Enid, is morbidly obese, his son, Harrison, lives an "alternative" lifestyle, and his other son, Trong Tri Kelso, is a love child from an affair with a Vietnamese woman.
One of the most famous unseen characters in TV history was Mrs. Columbo, Lt. Columbo's wife. Do you know what she looked like?
Unfortunately, "Columbo" fans did find out in the spin-off series "Mrs. Columbo," which starred Kate Mulgrew and only lasted 13 episodes. The show was disavowed by the producers of "Columbo" and maligned by many fans as sacrilege.
Do you know who Inspector Gadget's nemesis was?
It was Dr. Claw, who, in a parody of the old James Bond villain Ernst Stavro Blofeld, was never fully seen.
The role of the unseen Mammy Two Shoes on "Tom and Jerry" is today considered a racial stereotype, and the dialogue has been redubbed for airing on The Cartoon Network. Do you know who voiced the original role?
It was actress Lillian Randolph, who was on the also racially controversial "Amos N Andy" TV program in the 1950s, and is seen here opposite Harold Peary in the "Fibber McGee and Molly" spin-off TV sitcom "The Great Gildersleeve."
Do you know what Tim Taylor's neighbor, Wilson, looked like on the hit sitcom "Home Improvement?"
While "Home Improvement" made the faces of Tim Allen and Jonathan Taylor Thomas world famous, actor Earl Hindman's face remained hidden for the entire run of the show.
Do you know what actor played the Angels' never seen, only heard boss Charlie on the show "Charlie's Angels?"
Charlie wasn't just a mystery on the show. Actor John Forsythe recorded his role on tape, never visited the set and never even met two of the lead actresses from the show.
Do you know who Chandler's roommate was on "Friends" before Joey (Matt LeBlanc) moved in?
Chandler's old roommate, Kipp, was referred to often on the early seasons of "Friends," but never seen. There was also the unseen "Ugly Naked Guy" who lived across the way from Rachael and Monica.
Do you know who was the rambling voice of New York Yankees owner George Steinbrenner on the hit sitcom "Seinfeld?"
It was the show's co-creator, Larry David, now equally famous for writing, producing and starring in the Emmy-winning HBO show "Curb Your Enthusiasm."
Do you know who played the voice of Al Bundy's obese, unseen mother-in-law, who lived upstairs with the Bundys from time to time on the show "Married With Children?"
It was character actress Kathleen Freeman, best known for her role as Sister Mary Stigmata (a.k.a. The Penguin) in the 1980 film "The Blues Brothers."
Do you know who the unseen characters were on the TV specials for "Peanuts?"
The adults, including teachers and parents, were never seen and spoke in unintelligible "wa wa wa" voices.
Do you know who was the voice of the loving character named Nanny on the cartoon "Muppet Babies?"
It was Barbara Billingsley, best know for playing Mrs. Cleaver on "Leave it to Beaver."
The FBI is investigating a hacking attack on JPMorgan Chase that caused a data breach, though the extent of the damage from the attack and where it came from have not yet been determined. Take a look at some of the biggest data breaches of all time.
Diane Sawyer officially stepped down as anchor of ABC's "World News" last night, but will focus on primetime specials and big interviews for the network. Take a look at other high-profile personalities and their exits from particular shows or TV altogether.