The Original Darrin

Sometimes it's necessary in a franchise that a performer has to leave -- but the character they play can't just be Put on a Bus. So, they get recast, and the new performer takes over the role. The classic case, the Trope Namer for that in fact, is Bewitched and the replacement of the original Darrin Stephens, actor Dick York, by near-lookalike Dick Sargent.

That's not terribly uncommon, actually.

But then there are those cases when The Other Darrin now has to leave the franchise -- and The Original Darrin comes back to take over the role once again. Sometimes the audience never notices -- and sometimes they do, and they rejoice.

This trope covers all cases where the Other Other Darrin is the First Darrin. To qualify, the original performer needs to come back to the role he or she originated on a presumably permanent basis -- cameos (such as Tom Baker's return as a far-future version of The Doctor revisiting "a favorite face" in The Day of the Doctor) and one-offs (again, the various "The X Doctors" specials for Doctor Who) don't count. Sometimes, very rarely, a work (cough-Roseanne-cough) can end up in a sort of in-between state, but that's okay, it's still a case of this trope.

While it's most often seen in voice-only roles in animation and video games, cases do show up in other media, such as film franchises and even the occasional live-action TV series. When it's too obvious to ignore, it often turns out to be a Casting Gag or Stunt Casting.

Film

 * Aladdin and the King of Thieves had Robin Williams returning as the Genie from Disney's Aladdin after Dan Castellaneta replaced him in The Return of Jafar.
 * Diamonds Are Forever had Sean Connery return to play James Bond after George Lazenby played the character in On Her Majesty's Secret Service. According to Lazenby, he gave up the role because his agent saw James Bond as a passing 60s fad. While not part of the same continuity, his second return to the role in Never Say Never Again was marketed as such.

Live-Action TV

 * Played with -- and we mean that literally, as they were very playful about it -- with Lecy Goranson and Sarah Chalke as Becky in Roseanne. When Goranson took time off from the show to go to college, Becky was temporarily Put on a Bus; however, they brought her back before Goranson finished school, and cast Chalke, after which they took every opportunity to lampshade the replacement, starting with her very first line as Becky.  When Goranson's college schedule relaxed, she returned to the series -- but on a part-time basis: she and Chalke would swap out on the role depending on her availability.  And of course, that got lampshaded.
 * In one episode, both actresses appeared, recreating the opening sequence from The Patty Duke Show (although some thought it was the Marx Brothers' famous "mirror gag"). The second Becky appears at the Connors' doorstep which a pair of trick or treaters and cheerful attitude, Mark (the character's husband) remarks "this is like deja vu all over again" and Roseanne later comments "Gee, I wish we had a daughter that sweet."
 * In the Disney vacation episode, Becky's actresses changed again for that one episode (for Chalke's last appearance as Becky), and at one point Roseanne said to her, "Aren't you glad that you're here this week?"
 * Also, a Clip Show with a framing sequence set in the future featured John Goodman as an adult DJ, almost catatonic following some mysterious trauma in his childhood. He just kept repeating "They say she's the same, but she isn't the same."
 * Chalke and Goranson both returned for the 2018 revival of Roseanne (which later became The Connors). Although they no longer shared the role of Becky, there was still plenty of Lampshade Hanging to go around with the two of them, starting right from the first episode where Chalke plays Andrea, a woman looking to hire Becky as a surrogate mother, and the two of them spend time discussing how closely they resemble each other and how they could be the same person.

Professional Wrestling

 * Kevin Nash and Scott Hall played Diesel and Razor Ramon in royal rumbles, years after losing rights to play those roles to WWE when they left the company in 1996 and being replaced by Glenn Jacobs as Diesel and Rick Bognar as Razor Ramon, respectively. In-universe Diesel and Nash were acknowledged as the same person anyway.
 * Also in WWE, Luis Ignacio Urive Alvirde returned as Sin Cara after being injured, and his replacement was retconned into being a pretender.

Video Games

 * Kingdom Hearts II had Glenn Shadix returning to voice the Mayor of Halloween Town after Jeff Bennett voiced him in the first Kingdom Hearts game.
 * Prince of Persia: The Two Thrones had Yuri Lowenthal returning to voice the Prince after he was replaced by Robin Atkin Downes in Warrior Within.
 * Spider-Man 2 had Kirsten Dunst returning to voice Mary Jane after Catherine O'Conner voiced her in the 2002 game.
 * Spider-Man 3 had J.K. Simmons and James Franco returning to their roles from the films after being voiced by Jay Gordon and Josh Keaton respectively in the previous games.
 * For the video games based on the first two Michael Bay Transformers films, Frank Welker returned to voice Megatron after Hugo Weaving replaced him.
 * Star Trek: Voyager – Elite Force had the show's original cast reprise their characters except Jeri Ryan as Seven Of Nine, as she was unavailable at the time of production, and voice work from Joan Buddenhagen was used for her character. Star Trek Voyager Elite Force Expansion Pack would, in addition to its new content, replace Joan Buddenhagen's voice work in the original game with new voice work by Jeri Ryan.
 * In an odd triple example, James Bond 007: Agent Under Fire used an original James Bond played by Andrew Bicknell. After that James Bond 007: Nightfire used used Pierce Brosnan's likeness but an impersonator's voice. After that the next game, James Bond 007: Everything or Nothing would feature Brosnan's likeness and voice (though he doesn't talk much, presumably due to budget issues). After that EA would follow it with a video game based on From Russia with Love which got the original EON Bond Sean Connery to provide voice and likeness.

Western Animation

 * The Emperor's New School had John Goodman returning to voice Pacha in the second season after Fred Tatasciore replaced him.
 * The VeggieTales Show had Phil Vischer returning to voice Mr. Nezzer whenever David Mann is unavailable.