Each and every TV series, be it comedy, drama, action, or romance, starts with a foundation of a cast of characters. If the show is successful and finds an audience, those characters become fan favorites and will show up on the TVs of viewers for years to come. Season after season, these characters become a part of pop culture history, leaving behind iconic catchphrases like Columbo's "Just one more thing" or Steve Urkel's "Did I do that?"

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But sometimes, characters who were on the path to becoming iconic vanish from a show. They may be killed in a shocking twist or they may just vanish between seasons and never be mentioned again. But some character exits have stood out as ones that really stuck with the audience for years.

10 Valerie Killed The Main Character And Changed The Whole Premise Of The Show

The Hogan Family cast together.

In 1986, audiences turned their TVs to NBC to watch Valerie, a new series starring Valerie Harper. In the series, Harper played a working mom trying to essentially raise her three sons alone, as her husband was an airline pilot who was rarely home. During the second season, Harper entered negotiations on a new contract.

NBC chose not to renew the star's contract, but they didn't want to cancel the hit series either, so the decision was made that between the second and third season, Valerie would be killed off and replaced by the aunt of the three boys, changing the concept from a single mom raising her kids to cool aunt raising her sister's kids.

9 Star Trek: The Next Generation Killed A Main Character Early In The First Season

Star Treak Next Gen's Tasha Yar, played by Denise Crosby

These days it isn't uncommon for a TV series to kill off a character that appears to be important in the first season just to raise the stakes and make the audience think anything could happen, but in 1987 it was virtually unheard of. But that is exactly what happened in the 23rd episode of the first season of Star Trek: The Next Generation.

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Denise Crosby had been cast as Tasha Yar, the chief of security aboard the USS Enterprise. Yar was supposed to be a major character in the show, but as filming for the season went on. Crosby felt that her character was being ignored and asked to be let out of her contract. With the actress leaving, the decision was made to kill Tasha in what was an otherwise bland episode.

8 Troy Went On A Long Trip In Community

Conventions Of Space & Time Community Troy and Britta

In its fifth season, Community lost two characters. The first was Pierce Hawthorn, who died off-screen due mainly to actor Chevy Chase having left the show between seasons. Just a few episodes later, the show also had to deal with Donald Glover, who played Troy, leaving as well.

No one wanted to see Troy die, so the show came up with a unique way to have him leave the series. When the remaining members of the Greendale Seven are given their bequeathments from Pierce's will, most of the gang get a vial of Pierce's bodily fluids, but Troy is given $14 million dollars. There is a catch - to get the money, Troy first has to sail around the world in Pierce's yacht.

7 Gina Left The Nine-Nine With A New Monument

Brooklyn Nine-Nine Gina Linetti

Played by Chelsea Peretti, Gina wasn't the main character of Brooklyn Nine-Nine, but her irreverent humor and dance routines were a major part of what made the show work. When it was announced that Peretti would be leaving the series early in the sixth season, fans wondered how wild her exit would be, but no one was prepared for what happened.

In true Gina fashion, the civilian administrator of the Nine-Nine decided to become an influencer through her dance and said her goodbyes to the gang, but not before gifting them a gold statue of herself.

6 Doctor Who Came Up With A Way To Replace The Main Character Via Regeneration

The Doctors of New Who 2005-Present

With nearly six decades of stories, just about everyone knows the basics of Doctor Who. As a Time Lord, the Doctor is able to regenerate whenever they are badly injured or dying, but doing so gives them a new appearance and personality. While this has become a major part of Doctor Who, it wasn't in the original plans for the show. When William Hartnell, the man first cast as the Doctor in 1963, became too ill to continue working on the series, producer Innes Lloyd and story editor Gerry Davis came up with the idea of having the Doctor "die" and be "reborn" as a way to replace the actor and give an in-show reason for the change.

5 Bones Took The Idea Of Killing A Character And Turned It On Its Head

Temperance gets suspicious of Zack in Bones

In a series like Bones, where the characters investigate an endless stream of ghastly murders, it seems like the most obvious way to write a character out would be to have them get killed, but when it came to Dr. Zack Addy, the show's writers went in a different direction.

Instead of killing off Dr. Addy, the show revealed that Zack was actually working with a serial killer in the hopes of becoming one himself. The revelation rocked the crew of Bones to their core and shocked fans of the series.

4 Steve Left Blue's Clues For College

Steve and Blue from Blue's Clues.

A generation grew up yelling out at Steve from Blue's Clues as he worked to solve clues left by Steve's dog Blue. The show, which was always warm and loving, almost turned actor Steve Burns into a member of every family that watched, so it came as a shock to audiences when Steve left the series in the fourth season.

As Steve explained to his friends on the other side of the TV, he was going off to college on a hopscotch scholarship, and while saying goodbye is never easy, Steve had to leave so he could learn even more. It was a hard day for a lot of kids, but somehow the fans have always known Steve was still there for them.

3 Lt. Col. Henry Blake Almost Made It Out Of M*A*S*H*

Henry Black from MASH

On a show like M*A*S*H, which centered on the doctors of a mobile surgical hospital during the Korean War, death was always right around the corner. The show is iconic for its ability to switch between comedic moments and heartbreaking scenes that remind viewers that life is fleeting, and no moment did that better than the Season 3 finale, "Abyssinia, Henry."

In the episode, commanding officer Lieutenant Colonel Henry Blake is given an honorable discharge from the military and leaves Korea for home. The episode has a number of wonderful moments as the remaining doctors send off their friend, but the shock comes in at the final moment when it is revealed that Lieutenant Colonel Blake's plane was shot down over the Sea of Japan.

2 Erlich Bachman Found His Level In Silicon Valley

Silicon Valley Bachman

HBO's Silicon Valley was an instant hit, and a big part of that was T.J. Miller as Erlich Bachman. Bachman stood out from the rest of the characters on the show, primarily because of his open drug use and less-than-charming attitude, and those were the things that made fans love him.

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Miller left Silicon Valley at the end of the fourth season, and the show decided to explain Bachman's disappearance in a way that would only work with this character. In the season finale, Bachman finds himself feeling right at home in an opium den in Tibet. While the show continued for two more seasons, Bachman was never seen again.

1 Maude Flanders Caught A Shirt

Maude Flanders looking down from The Simpsons

While it's common for live-action TV shows to write characters out of the story, it's much rarer in animation. Usually, if an actor wants to leave an animated series, they will just be replaced with a new actor who has a similar voice, but for The Simpsons, when Maggie Roswell left the show over a pay dispute, the decision was made to kill off her character, Maude Flanders.

In true Simpsons style, Maude's death couldn't be something fans could see on another series. For this character who had been on the series for eleven seasons, the only way to kill her off was to have her be bombarded by t-shirts shot out of cannons.