The stage direction “Exit, stage left” was the catchphrase of the cartoon lion Snagglepuss, whose cartoons appeared on The Yogi Bear Show in the 1960s. The line indicated that Snagglepuss was leaving the situation. The expression is still used.
     
The 7-minute cartoon Major Operation originally aired on January 30, 1961. Snagglepuss says “Exit, stage left” twice and “Exit, stage right” once.
     
   
Wiktionary: exit, stage left
Etymology
From the direction in theatrical scripts: “Exit stage left”, marking the disappearance of a character from the stage in the normal manner.
Noun
exit stage left (plural exits stage left)
1. (idiomatic) An orderly and uneventful departure, timed so as not to detract or distract.
Verb
exit stage left (third-person singular simple present exits stage left, present participle exiting stage left, simple past and past participle ,i>exited stage left)
1. To exit or disappear in a quiet, non-dramatic fashion, making way for more interesting events.
2. (imperative) Leave the scene, and don’t make a fuss.
     
Wikipedia: Snagglepuss
Snagglepuss is a Hanna-Barbera cartoon character who debuted in prototype form in 1959 and established as a studio regular by 1961. A light pink anthropomorphic cougar sporting an upturned collar, shirt cuffs, and bow tie, Snagglepuss enjoys the fine things in life and shows particular affinity for the theatre. His stories routinely break the fourth wall as the character addresses the audience in self-narration, soliloquy, and asides. As originally voiced by Daws Butler, Snagglepuss seeks quasi-Shakespearean turns of phrase. Some of his campy verbal mannerisms became catchphrases: “Heavens to Murgatroyd!”, “Exit, stage left!”, and a fondness for closing sentences with the emphatic “even.”
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Before dashing offscreen to make an escape or run an errand, Snagglepuss announces the move in the form of a theatrical stage direction, saying “Exit, stage left!” (or “right,” as the case may be, or “up” or “down” even).
     
IMDb
Major Operation
Episode aired Jan 30, 1961
7m
Major Minor, the game hunter, has lost face and may be forced out of the Adventurer’s Club unless he can do something startling -like catching the wily lion, Snagglepuss, who has eluded him for years. The Major approaches Snagglepuss in Snag’s cage at the city zoo. He makes a deal: he will release Snag if the lion will consent to being recaptured. Snagglepuss consents and the Major is restored to his former eminence in the club.
Directors  Joseph Barbera William Hanna
Writers Joseph Barbera William Hanna Michael Maltese
Stars Daws Butler (voice) Don Messick (voice) Renzo Palmer (voice)
 
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Zombie Cartoon Lovers
June 17, 2020 ·
Snagglepuss - 1x01 - Major Operation
2:13
“Exit, stage left.”
3:15
“And one second to exit, stage right.”
4:55
“Exit, stage left.”
 
Newspapers.com
31 January 1961, The Herald-News (Passaic, NJ), “Television In Review” by Fred Danzig (UPI), pg. 18, col. 6:
Parents who want to watch “The Yogi Bear Show” with their children are warned, however, that the youngster may interrupt their concentration to ask, “What does Yogi mean by, ‘exit stage left’” ...
 
Newspapers.com
23 March 1961, Akron (OH) Beacon Journal, “The Radio-TV Mailbag: Giving Credit To ‘Snagglepuss’” by Dick Shippy, pg. 14, col. 1:
You said that Yogi Bear sprints about Jellystone Park yelling “exit, stage left.” That isn;t Yogi, but a mountain lion named Snagglepuss. (...) YOGI BEAR FANS
 
Newspapers.com
18 June 1961, Sunday World-Herald (Omaha, NE), “Hanna-Barbera’s Yogi Bear” (comic strip), comic sec.:
AND LIKE SNAGGLEPUSS SAYS…EXIT STAGE RIGHT!
 
Newspapers.com
17 July 1961, Evening Journal (Wilmington, DE), “Man About Town” by Carl G. Smith, pg. 14, col. 7:
SNAGGLEPUSS, the odd TV lion, has taught a generation of children to say, “Exit, stage left.”
   
Wikipedia: Exit… Stage Left
Exit… Stage Left is the second live album by the Canadian rock band Rush, released as a double album in October 1981 by Anthem Records. After touring in support of their eighth studio album Moving Pictures (1981), the band gathered recordings made over the previous two years and constructed a live release from them with producer Terry Brown. The album features recordings from June 1980 on their Permanent Waves (1980) tour, and from March 1981 on their Moving Pictures tour.
     
YouTube
Snagglepuss Exit Stage Left
Claudia Scimeca Art
Oct 19, 2011
Exit Stage Left
 
Wikipedia: Exit, Stage Left!: The Snagglepuss Chronicles
Exit, Stage Left!: The Snagglepuss Chronicles is a satirical comic book, published by DC Comics, that reimagines the Hanna-Barbera cartoon character Snagglepuss as a gay playwright in the 1950s being victimized under McCarthyism. The comics make regular reference to real-life events and historical figures, including subplots about the blacklisting of Dorothy Parker and Lillian Hellman, Marilyn Monroe’s affair with Arthur Miller, the execution of Julius and Ethel Rosenberg, and the testing of the first hydrogen bomb.
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Publisher DC Comics
Schedule Monthly
Publication date 3 January 2018 - 6 June 2018
   
Theatre Geekery
Thursday, October 18, 2018
Exit, Stage Left - Theatre Etymology - Part 34
When most people hear “Exit, stage left,” they probably think of the pink mountain lion, Snagglepuss, that was created by Hanna-Barbera. It wouldn’t be surprising since that is one of his catchphrases, the other being “Heavens to Murgatroyd!” The phrase “Exit, stage left,” has come to mean quite a few things instead of just the typical exiting off of a stage.
   
Twitter 
anonbinary
@Binary_Anon
Replying to @StephenKing
Here’s another one to learn ” exit stage left” nobody wants to hear from you.
10:39 PM · Dec 6, 2022
 
Twitter
Olivia
@oriviebot
I can’t help anyone, limping like this… Time to exit… stage left…
2:13 AM · Dec 7, 2022