1. "The Gooch" on Diff'rent Strokes

School bully "The Gooch" haunted Arnold, Sam and friends throughout the series. His intimidating tactics compel Arnold to take karate lessons. "I'm mean, Gooch, mean," he growls into the telephone in "Return of the Gooch." Two seasons later, Arnold steals a comic book to gain entry into the Gooch's gang. Later still, a foreign exchange student named Carmella helps Sam fight the Gooch. But we never see the Gooch.

2. Robin Masters on Magnum, P.I.

Magnum lives on a beautiful oceanfront estate known as the Robin's Nest, at the behest of a famous author named Robin Masters. Masters' caretaker, Higgins, is a major player in the adventures of Magnum, P.I. We never see Master Masters, though. The venerable Orson Welles voiced the character in a handful of episodes.

Image: The Everett Collection

3. Peggy's mother on Married… with Children

Al Bundy consistently grumbles about and mocks his in-laws, the Wankers. The bitter, beaten shoe salesman particularly takes jabs at Peggy's mother, who we gather is obese. Later in the series, the mother-in-law moves into the Bundy home. Yet we never see the character. Divine, the performer best known for roles in John Waters' cult films, seen here in Hairspray, was reportedly slated to play the role before passing away in 1988. Tim Conway ended up playing Peggy's dad, Ephraim Wanker.

Image: The Everett Collection

4. Vera Peterson on Cheers

Norm Peterson says the only reason he goes to Cheers is to get away from his wife, so it's fitting we never see her throughout the series. We do get to catch a glimpse of her body and hear her voice, only to have her face hidden by a smashed pie. The woman in that scene, Bernadette Birkett, is George Wendt's wife in real life.

5. Urkel's parents on Family Matters

Steve Urkel always seemed to hang around the Winslow clan in this family sitcom. The reason behind his constant presence was surprisingly kind of dark. Urkel claimed that his parents could not stand his presence. The elder Urkels eventually move to Russian and abandon their son, who moves in with the Winslows. Leaving your kid behind for Russia? Now that's cold.

Image: The Everett Collection

6. Kimmy's parents on Full House

Like Urkel, Kimmy Gibbler was another quirky neighbor who always seemed to be around. In fact, her mom even grounds her at the Tanners at one point. But we never see Mrs. Gibbler, nor her husband. But the Gibblers weren't so mean. They even paid for Kimmy to go to Disney World with the Tanners.

Image: Warner Bros. Television

7. Phil Petrillo on The Golden Girls

Sophia's son and Dorothy's older brother, Phil Petrillo was a cross-dresser. He also was skilled at dairy arts — every Christmas he built his mother a Nativity scene made of cheese. We do meet and see his wife, Angela Petrillo (Brenda Vaccaro), in one episode. In 1990, poor Phil passes away from a heart attack when trying on a dress.

Image: The Everett Collection

8. The Blue Leader on Scarecrow and Mrs. King

Lee Stetson, a.k.a. "The Scarecrow," works for the secretive Agency, helmed by the mysterious Blue Leader. Divorced housewife Amanda King ends up working for the Agency, too. That's the basic plot. We see the Scarecrow's immediate supervisor, section chief Billy Melrose, played by Mel Stewart, who previously portrayed Henry Jefferson, George's brother. We do hear the voice of Blue Leader a couple times, delivered by Byron Morrow, who played an Admiral in two episodes of Star Trek.

Image: The Everett Collection

9. Dr. Claw on Inspector Gadget

"I'll get you next time, Gadget… next time!" So would end most episodes of Inspector Gadget, as the evil nemesis smashed his computer keyboard with his iron gauntlet. The metal hand is all we saw of Dr. Claw. His pet, Madcat, got far more screentime. An action figure was eventually released showing his face, and the regrettable toy looked a bit like Ted Baxter with lockjaw.

Image: Lexington Broadcast Services Company

SEE MORE: Other TV characters we all know, but never actually saw

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