A recent resurgence of  successful spin-offs, such as The Flash (from The CW's Arrow) and Better Call Saul (from AMC's Breaking Bad), gives us hope for next week's premiere of Fear the Walking Dead, a quasi-prequel spin-off of AMC's wildly popular The Walking Dead. The Walking Dead brought Robert Kirkman’s comic book to live-action as the series followed a group of survivors in southeast U.S. after a zombie apocalypse ravaged the world. Set on the other side of the U.S., in Los Angeles, Fear the Walking Dead will follow a family during the outbreak of the zombie virus.

But spin-offs can be a tricky thing for networks. On the one hand, a spin-off theoretically comes with a built-in audience. On the other, many spin-offs have promptly disappeared into obscurity upon their release, like NBC's ill-fated Joey, which followed the travails of Joey Tribbiani (Matt LeBlanc) from the uber-popular Friends. The good news is that some spin-offs become so popular that they eclipse the original shows, causing people to forget they were spin-offs entirely. To celebrate Fear the Walking Dead, we've created a list of 10 Hit Shows You Didn't Know Were Spin-Offs.

10. The Simpsons (from The Tracy Ullman Show)

THE SIMPSONS: The "Pulpit Friction" episode of THE SIMPSONS airing Sunday, April 28, 2013 (8:00-8:30 PM ET/PT) on FOX.. (Photo by FOX via Getty Images)

The Simpsons, also known as the longest running American sitcom, actually had its roots in a variety show most people don't remember - The Tracy Ullman Show, which premiered in 1987 and ran for just four short seasons. The Simpson family would appear in short animated segments during the first three seasons of the popular variety show before the network decided to give the cartoon family their own thirty minute sitcom. The cartoon shorts, called "bumpers," were written by Matt Groening and voiced by Tracy Ullman Show cast members. In 1992, Tracy Ullman even sued Fox for a share of The Simpsons' merchandising and gross profits because of her show's role in the series success - a case she ultimately lost.

While The Tracy Ullman Show won several Emmys in its day, The Simpsons has certainly passed its predecessor in terms of cultural impact and popularity. Over its 26 seasons, it has spawned a movie, video games, comic books, and catchphrases. Widely considered one of the greatest shows of all time, The Simpsons has garnered dozens of awards since it premiered in 1989. The series arguably paved the way for prime time animation, leading to other 1990s animated sitcoms like King of the Hill and Family Guy.

9. Frasier (from Cheers)

Frasier

While Frasier is one of the most popular spin-offs in television history, many people don't know that it's the spawn of Cheers, an equally popular show. Many people never put the shows together simply because of their wildly different tones: Cheers is set almost exclusively in a bar in Boston and revolves around a large ensemble cast, while Frasier focuses on an intellectual psychiatrist and his family living in Seattle. But the character of Frasier Crane (Kelsey Grammer) first appeared in season 3 of Cheers, and he remained a series regular until the show ended.

Frasier, like Cheers before it, aired for 11 seasons. During that time, every regular cast member from Cheers (except Kirstie Alley) made a guest appearance on the series. Added up, Grammer played the character of Frasier Crane for 20 years, and his portrayal of Crane was nominated for an Emmy on 3 different shows (including a crossover appearance on Wings). Interestingly, the Frasier set was actually built on the same stage Cheers was built on, despite ostensibly being set on the other side of the nation. Incidentally, Cheers also launched another, much less-successful spin-off called The Tortellis, which ended after just thirteen episodes.

8. Beavis and Butt-head ( from Liquid Television)

Beavis and Butt-head

Another spin-off that far surpassed its predecessor's popularity, Beavis and Butt-head is an animated series following two teenagers of questionable intelligence that started as part of MTV's Liquid Television, an animation showcase that aired for three seasons. In the original show, independent animators created short cartoons, which would be showcase in recurring segments. After appearing on Liquid Television, MTV hired Judge to give Beavis and Butt-head their own half-hour show.

During its time on air, Beavis and Butt-head spawned a full-length theatrical film, a Marvel Comics (under the Marvel Absurd imprint) series, and several video games. The show's character Daria Morgendorffer even received her own spin-off show, Daria, though Judge was not involved in that. Beavis and Butt-head originally aired for 7 seasons from 1993 to 1997 and was brought back from the dead for an eighth season in 2011 on MTV.

7. The Jeffersons (from All in the Family)

The Jeffersons

The Jeffersons followed a wealthy African-American couple after they move from a working-class section of Queens, New York into a luxury apartment in Manhattan (also known as a deluxe apartment in the sky). But prior to this big movie, the Jeffersons actually lived next door to the Bunkers in a sitcom called All in the Family. Archie and Edith Bunker encounter the Jeffersons during their show's first season in 1971, when Archie has trouble accepting that the Jeffersons are the neighborhood's first African-American family. The Jeffersons continued to sporadically appear on the series until their spin-off premiered in 1975.

Both shows were beloved in their time and had lasting cultural impacts, but The Jeffersons ran for eleven seasons compared to All in the Family's eight. The Jeffersons even spawned its own spin-off, called Checking In, which followed the Jefferson's housekeeper, but it lasted only four episodes. If you count spin-offs from spin-offs, All in the Family has had more spin-offs than any other prime-time television show. The popular series Maude and its spin-off Good Times also originated in All in the Family.

6. NCIS (from JAG)

NCIS

One of the longest-running one hour dramas in television history, NCIS follows a fictional team of Naval Criminal Investigative Service agents. The characters were originally introduced in JAG, a show following the Judge Advocate Generals of the United States Navy, with the NCIS characters showing up in two episodes of JAG's eighth season. This two-episode "back door pilot" introduced the NCIS team of the new show, including the leader Gibbs (Mark Harmon), agent Tony (Michael Weatherly), forensic specialist Abby (Pauley Perrette), and medical examiner Ducky (David McCallum).

JAG ended its ten season run in 2005, while NCIS will air its thirteenth season this fall. Despite its long run, NCIS shows no signs of slowing down anytime soon. For the past several seasons, NCIS has consistently ranked as one of television's most watched shows. NCIS went on to spawn its own spin-offs, NCIS: Los Angeles and NCIS: New Orleans, both of which have become popular in their own rights.

5. The Facts of Life (from Diff'rent Strokes)

The Facts of Life

One of the most beloved series of the '80s, The Facts of Life follows Edna Garrett (Charlotte Rae), a house mother at a fictional all-female boarding school, and the girls in her care, including Blair (Lisa Whelchel), Tootie (Kim Fields), and Natalie (Mindy Cohn). But before becoming house mother, Edna starred as the Drummond housekeeper on Diff'rent Stokes, a show about two African-American boys taken in by the rich, white businessman, Mr. Drummond (Conrad Bain). Edna's time on Diff'rent Strokes was short-lived - she appeared on only the first and second season - and The Facts of Life cast was introduced on the last episode of the Diff'rent Strokes first season.

The Facts of Life was only marginally successful in its first season. The network extensively retooled it in season 2 by cutting a large number of the cast and moving it to a new time slot. By its third season, it was ranked higher than its predecessor and went on to become even more successful, ending after nine seasons (compared to Different Stroke's eight seasons).

4. Family Matters (from Perfect Strangers)

Family Matters

From the little-remembered sitcom Perfect Strangers came the cultural icon that is Steve Urkel (Jaleel White). Family Matters was meant to follow Harriette Winslow (Jo Marie Payton), who had first appeared as an elevator operator in the third and fourth seasons of Perfect Strangers, and her middle-class African-American family. In order to explain Harriette's absence on Perfect Strangers, she was fired from her job in the second episode of Family Matters. The new show only became successful after the accident-prone, nerdy character of Steve Urkel appeared halfway through the first season. By season two, the show's focus transitioned from the Winslow family to him.

Urkel and his suspenders quickly cemented a spot in the history of pop-culture with his catch-phrase, "Did I do that?" and a tenure on ABC's popular TGIF Friday night line-up. During the show's run, he even crossed-over as Urkel in a number of other early 90's shows, including Full House and Step by Step. Like many shows in this list, Family Matters went on to have a longer run than its predecessor, reaching 9 seasons before it was cancelled.

3. Mork & Mindy (from Happy Days)

Mork and Mindy together on Mork and Mindy

You could be forgiven for not realizing Mork & Mindy, a show about an alien sent from Ork to study Earth, was actually a spin-off of the classic (and comparatively realistic) American sitcom Happy Days. Mork from Ork (Robin Williams) made his first appearance on season 5 of Happy Days when he attempted to take star Richie Cunningham (Ron Howard) back to his home planet, only to be stopped by the Fonze. The Happy Days writers originally intended for the episode to be nothing more than a dream sequence since the show was not known for having sci-fi/fantasy elements. But Williams' portrayal of Mork proved to be so popular that the episode was re-edited with a new ending, which had Mork erase the memory from everyone's minds, and allowed the character to continue in his own spin-off series.

Mork & Mindy was a ratings hit for a year after it premiered, but it quickly lost steam and ended after only four seasons. Happy Days, which was itself a spin-off of Love, American Style, actually launched seven spin-off series total, including four live actions and two cartoons. Its most popular was Laverne & Shirley, which followed two brewery workers first introduced on Happy Days and ran for eight seasons. So while Mork & Mindy wasn't Happy Days' most successful spin-off, the content still makes it the most surprising.

2. The Muppet Show (from Sam and Friends and Sesame Street)

The Muppet Show

Kermit technically made his television debut in Sam and Friends, a live-action/puppet show created by Jim Henson in 1955 that aired on a local Washington, D.C. channel. He was voiced by Jim Henson (who continued to voice Kermit until his death in 1990), but his early incarnation had a lizard-like appearance. The original Kermit design currently resides in the Smithsonian museum in Washington. It wasn't until the premiere of Sesame Street that the idea of "Muppets" took off. Shortly before making his first appearance on Sesame Street, Kermit transitioned into the recognizable green frog everyone knows and loves.

Sesame Street ran for five years before Jim Henson created The Muppet Show, which brought with it Kermit the Frog and some new friends. Over the years, The Muppet Show has become its own beloved franchise (including eight feature films) and has launched its own spin-offs, including the long-running animated series Muppet Babies. Currently, ABC is developing a revival of the Muppet Show, which will be a mockumentary-style series.

1. Saved by the Bell (from Good Morning, Miss Bliss)

Saved by the Bell cast sat together at a desk while looking up

Most spin-offs come from already popular shows with the hope that the spin-off will benefit from the predecessor's built-in audience. But that wasn't the case with Saved by the Bell, which spun-off from a poorly rated thirteen episode Disney Channel series called Good Morning, Miss Bliss. Like it's successor, this series featured Zack (Mark-Paul Gosselaar), Screech (Dustin Diamond), Lisa (Lark Voorhies), and Mr. Belding (Dennis Haskins), but the short-lived Miss Bliss focused on the life of a teacher named Miss Bliss (Hayley Mills) instead of her teenage students. Saved by the Bell switched the focus, cut Miss Bliss from the cast, and added additional student cast members - including Slater (Mario Lopez) and Kelly (Tiffani-Amber Thiessen).

While Saved by the Bell also made some continuity changes (like relocating the school from Indianapolis to the fictional California suburb of Bayside), the network treated the series as a spin-off. Episodes of Good Morning, Miss Bliss were included in Saved by the Bell's syndicated rerun package, and Zack provided an introduction for each episode to explain that they were from an earlier time. Saved by the Bell went on to spawn two of its own spin-offs, Saved by the Bell: The College Years and Saved by the Bell: The New Class, but neither managed to live up to the popularity of the original.

Last year, the Lifetime channel fictionalized the behind-the-scenes drama of Saved by the Bell (which included the transition from Good Morning, Miss Bliss) in The Unauthorized Saved by the Bell Story, which was based on Dustin Diamond's 2009 book Behind the Bell.

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Those were just 10 of the shows we were surprised to discover were spin-offs. Did you see any of the original shows? What other spin-offs eclipsed their predecessors? Do you think Fear the Walking Dead will be able to surpass the popularity of The Walking Dead? Let us know in the comments!