[[quoteright:350:http://static.tvtropes.org/pmwiki/pub/images/WBK_4051.jpg]]
[[caption-width-right:350:''Magazine/{{Mad}}'s'' Jack Davis is drawing us for the ''Magazine/TVGuide'' cover? Very impressive, Mr Kotter!]]

->''"Hey Julie....did I ever tell you about my [[EndOfEpisodeSilliness Uncle Fremont Kotter]].....?"''

Before Jerry Series/{{Seinfeld}} wondered about airline peanuts, before Tim Allen said his first [[HomeImprovement "Arrr arrr arrr!"]], before {{Roseanne}} became a Domestic Goddess, there was Gabriel Kaplan, the first stand-up comedian to successfully turn his comedy routines into a hit sitcom. ''Welcome Back, Kotter'' ran on Creator/{{ABC}} from 1975 to 1979.

Gabe Kotter, formerly a Sweathog, returns to James Buchanan High School as a teacher and is assigned the remedial class to which he once belonged. Mr. Kotter is an involved and caring teacher, which one would have to be in dealing with a certain four students in his class, who end up in trouble on a regular basis: ladies' man Vinnie Barbarino, the always cool Freddie "Boom-Boom" Washington, the tough Juan (Luis Pedro Phillipo de Huevos) Epstein, and the sheepish Arnold Dingfelder Horshack. ''Welcome Back, Kotter'' was based on Gabe Kaplan's own high school experiences with remedial education and a teacher who cared dearly for her students.

Changes on the show: Gabe Kaplan left the series in the third season, due to creative differences with executive producer James Komack. Kaplan openly felt that Komack was not serving the show's best interests. Kotter was made vice principal, and thus was seen considerably less. JohnTravolta, of course, found his own place as a celebrity, leaving the show around the same time Gabe Kaplan did (returning every so often as a "special guest star"). The replacement for Barbarino was Beau, who didn't help things much. By now the show had essentially lost its two biggest stars.
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!!''Welcome Back, Kotter'' contains examples of:

* AndStarring: John Travota's billing during his last season on the show.
* BabiesMakeEverythingBetter: Julie gives birth to twin girls.
* BerserkButton: Don't say anything bad about Barbarino's mother.
-->'''Barbarino:''' Hey! NOT my mother. That woman's completely holy!
* BigScrewedUpFamily: Juan Epstein.
-->'''Epstein''': I don't have to stay here and be ignored! I have nine brothers and sisters. If I want to be ignored, I'll just go home.
* CatchPhrase: "Up your nose with a rubber hose" (everyone), "Hi, there" (Washington), "Heyyyy Misssster Kotttaire!" (Washington),"What?" "Where?" (Barbarino), "I'm so confused!" (Barbarino), "Ohhh ohh ohh ohh!" (Horshack), "Very impressive, Mr Kotter!" (Horshack)
* CloudCuckoolander: Everyone had their moments, but Horshack is ''the'' definitive example.
* CommutingOnABus: Mr. Kotter's appearances in the last season were very sporadic, as Kaplan had become discontent with the direction of the show. Mrs. Kotter becomes the new mentor of the Sweathogs.
* DeanBitterman: Mr. Woodman
* EarlyInstallmentWeirdness: In the pilot, Horshack is implied to be a CovertPervert who apparently wasn't allowed to talk unless Barbarino told him too. Barbarino also seemed to have a regular sweathog-girlfriend. The Sweathogs were actually a tad more intimidating.
* EndOfEpisodeSilliness: Formerly the TropeNamer when it was called "Uncle Herbie".
* EnterStageWindow: The Sweathogs routinely drop in on their favorite teacher via his living room window. Doesn't bother him any, but his wife doesn't like it.
* EveryEpisodeEnding: Gabe tells Julie an amusing anecdote about one of his many relatives at the end of every episode.
* FiveManBand:
** TheHero: Vinnie, later relegated to The Sixth Ranger when John Travolta's movie career started taking off
** TheLancer: Freddie. Beau in the final season when Freddie was seemingly promoted to leader
** TheBigGuy: Epstein
** TheSmartGuy: Horshack
** [[TheChick RevolvingDoorChicks]]: Rosalie Totsie, Vernajean Williams, Angie Grabowski, Mary Johnson
** The Mentor: Gabe Kotter
* FourTemperamentEnsemble: The Sweathogs: Barbarino (melancholic), Epstein (choleric), Horshack (sanguine), and Washington (phlegmatic).
* FurryFandom: In one episode Kotter wears a chicken suit in a restaurant to raise extra money for emergency dental work
* GRatedDrug: In the episode "What Goes Up ... ", Freddie becomes addicted to painkillers (to heal a basketball injury); a naive Horshack takes Freddie at his word that said pills are "vitamins," while the others are well-aware that Freddie is becoming dependent on them.
* GeorgeCarlin: Guest starring as radio DJ Wally the Wow, and as Wally the Weasel, a former Kotter-era Sweathog.
* TheGhost: Principal Lazarus.
* Magazine/{{MAD}}: ''Welcome Back, Klodder''.
* MarxBrothers: Often imitated, with Epstein as Chico, Horshack as Harpo, and Kotter as Groucho.
** Notably, Gabe Kaplan did a one-man show as Groucho Marx during the height of the show's popularity.
* TheMerch: Several novel sized paperback with original stories, a comic book, a lunchbox, a "Welcome Back, Kotter" [[BoardGames board game]], and Sweathog action figures with a classroom play area.
* NeverWinTheLottery: In one episode Kotter chips in a quarter for the Sweathogs weekly lottery ticket when one of them comes up short. When the ticket then wins, the Sweathogs try to just give Kotter back his 25 cents instead of a share of the winnings.
* NobodyTouchesTheHair: Barbarino is like this.
* OnceAnEpisode: Kotter tells a joke about one of his relatives.
* TheOneWhoMadeItOut: Gabriel.
* RealLifeWritesThePlot: One two part episode had Kotter trying to start a stand up career.
* RunningGag: Epstein's never ending supply of excuse notes, almost always signed "Epstein's Mother".
** Julie's infamous tuna cassarole.
* SignatureLaugh: Horshack's athsmatic laugh.
* SuspiciouslySimilarSubstitute: Beau De Lebarre as Vinnie's replacement
* ThematicThemeTune: In fact, the producers of what was originally going to be called ''Kotter'' thought John Sebastian's "Welcome Back" captured the tone of the show so well they renamed the show after it.
* ThemeTuneExtended: "Welcome Back" was originally just one verse. [=DJs=] suggested recording a full-length version to Sebastian. He did, and it became a #1 hit.
* TranslationMatchmaking: In Italy it's known as ''I Ragazzi del Sabato Sera'' (''Saturday Night Guys''), after ''SaturdayNightFever''.
* TwoferTokenMinority: Puerto-Rican Jew Juan Epstein.
* UglyGuyHotWife: Gabe and Julie, though Gabe is more plain/quirky-looking than ugly
* VerySpecialEpisode: "What Goes Up," the Season 3 episode where Boom Boom got addicted to painkillers to heal a basketball injury. Boom Boom is in deep denial, and so is a shaken Horshack who naively believes Boom Boom's explanation that the pills are "vitamins." The others aren't so fooled and eventually get Boom Boom to realize what he's doing. In the final season, "Come Back, Little Arnold" has Horshack using booze to boost his courage when asking out a new love interest. He snaps out of it after he accidentally punches her out while aiming for one of the guys.
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