Some of our favorite TV characters weren’t even on their shows when they first debuted.
Sure, it’s nice when a show hits upon the perfect cast combination right away — we’re looking at you, Friends — but most shows need to retool a bit in later seasons, either to replace a departing cast member or just to bring in some new blood. Not all of the cast additions work, of course; many shows have fallen victim to the dreaded Cousin Oliver Syndrome, adding an ill-conceived character that ends up sinking the whole series. But in a few fortunate cases, a late addition can actually improve a show, to the point where we can’t picture the cast without them.
We here at TVLine looked through the TV history books and picked out more than 30 characters who weren’t a part of their show’s very first season, but still ended up making an indelible impression on that show’s legacy. We’ve got game changers from all-time great comedies (Seinfeld, The Office, Sex and the City) and dramas (Lost, Breaking Bad, ER) who may have arrived late, but definitely livened up the party when they did.
Read on to see which late cast additions made our list, and then hit the comments below to add your own favorites.
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Chloe O'Brian, 24
Image Credit: Everett Collection Mary Lynn Rajskub’s Chloe quickly became a fan favorite after arriving to CTU in Season 3. While her irksome personality weighed heavily on her colleagues, she was a joy for us viewers, and eventually grew to become Jack Bauer’s No. 1 friend and confidant. Chloe repeatedly stuck her neck out for Jack, and her unwavering loyalty earned both his and our respect. The character became such a 24 staple that we can’t possibly imagine the series without Rajskub’s stellar comedic timing and scowls.
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Amy Farrah Fowler and Bernadette Rostenkowski, The Big Bang Theory
Image Credit: Everett Collection The additions of Mayim Bialik’s Amy and Melissa Rauch’s Bernadette (first as guest stars in Season 3, then as full-fledged series regulars in Season 4) were essential to the extending the lifespan of the CBS sitcom, whose previous gender imbalance limited storytelling opportunities. Bialik would go on to bank four consecutive Emmy nominations for her turn as Sheldon’s extremely patient girlfriend (and later, wife). And we have Rauch’s Bernie to thank for Howard’s transformation away from the walking sexual harassment lawsuit Simon Helberg embodied in the first three seasons.
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Mike Ehrmantraut, Breaking Bad
Image Credit: Everett Collection Weirdly, we have How I Met Your Mother to thank for Mike Ehrmantraut’s existence. Breaking Bad‘s Season 2 finale “ABQ” was originally supposed to feature Bob Odenkirk’s Saul Goodman, but Odenkirk was busy filming HIMYM, so the writers created a new character to help clean up after Jane’s death. The gruff underworld fixer was supposed to be a one-off, but Jonathan Banks made such a big impression as Mike, he came back for Season 3 and became a key part of the Breaking Bad ensemble, even reteaming with Odenkirk for six seasons of the spinoff Better Call Saul.
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Spike, Buffy the Vampire Slayer
Image Credit: Everett Collection The peroxided bloodsucker played by James Marsters first showed up in Season 2’s “School Hard” episode and quickly established himself as a villainous nemesis whose fighting prowess — and ability to land a pithy quip — rivaled Buffy’s. He eventually (and grudgingly) became an ally of sorts for the slayer and her friends; when he fell in love with Buffy in Season 5, things got really interesting.
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Frasier Crane, Cheers
Image Credit: Paramount screenshot NBC’s beloved bar comedy did a superb job of replacing Diane with Rebecca and Coach with Woody, but its greatest addition might have been the pompous psychiatrist played by Kelsey Grammer, who joined the cast in Season 3 as Diane’s therapist/boyfriend. Diane left, but Frasier stuck around, acting as the stuffy intellectual counterweight to the beer-swilling Cheers gang — and he even landed his own spinoff, Frasier, which ran for 11 seasons of its own.
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Leon Black, Curb Your Enthusiasm
Image Credit: Courtesy of HBO In Curb‘s early seasons, Larry David was sort of a comedy lone wolf, though he had pal Jeff to egg him on and wife Cheryl to frown at his latest hi-jinks. But in Season 6, Larry took in a family of Hurricane Katrina victims, including the fast-talking Leon, played with effortless cool by J.B. Smoove. With his bluntly honest approach to life, Leon added a whole new dimension to Curb‘s comedy and gave Larry an unlikely — but actually perfect — partner in crime.
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Jack and Andie McPhee, Dawson's Creek
Image Credit: Everett Collection The brother-and-sister duo played by Kerr Smith and Meredith Monroe moved to Capeside in Season 2 and immediately shook up the show’s romantic storylines. During the course of their relationship, Andie helped show off a new, tender side of Pacey, while Jack drove a wedge between Dawson and Joey before coming out in one of the series’ most significant storylines. Monroe’s character was eventually written out in Season 4, but Jack remained an integral part of the group, especially as Jen’s BFF, to the very end.
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Alexis Carrington, Dynasty
Image Credit: Everett Collection Gorgeous women in glamorous gowns beating each other to a pulp was a staple of this ‘80s primetime soap, with the brawls between Alexis (Joan Collins) and Krystle (Linda Evans) being the most iconic of all. That makes it even harder to believe that this show existed for an entire year before it made the game-changing — and perhaps show-saving — decision to bring on Collins as the devious matriarch of the Carrington clan in the Season 2 premiere. What would Dynasty have been without her sharp-tongued takedowns, multiple marriages and bottomless bag of evil schemes? Thankfully, we’ll never have to know.
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Luka Kovač and Abby Lockhart, ER
Image Credit: Everett Collection When George Clooney and Julianna Margulies scrubbed out, Goran Visnjic and Maura Tierney scrubbed in! Luka and Abby’s on-again/off-again relationship would prove as central to latter-day ER as Doug and Carol’s relationship was in those first few seasons, and their respective backstories — Luka’s first wife and two small children perished in war-torn Croatia; Abby struggled with sobriety after growing up with a mentally unstable mom — went a long way toward helping viewers warm to them individually.
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Jo Polniaczek, The Facts of Life
Image Credit: Everett Collection Ahead of the NBC comedy’s sophomore season, four Eastland Academy students were “expelled,” so to speak, and one newbie enrolled: Nancy McKeon’s hard-edged biker chick, the antithesis of — and perfect foil for — snooty, superficial Blair Warner. Turned out that push/pull was just what the show needed; Season 2 saw it moved from ratings probation to the network’s honor roll.
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Rebecca Donaldson (aka Aunt Becky), Full House
Image Credit: Everett Collection Forget what you might think of Lori Loughlin now. Rebecca Donaldson was the strong female character the series so desperately needed upon her introduction in Season 2. She was a career woman first, and Jesse’s love interest second. Even before she married into the family, her role as surrogate mom to DJ, Stephanie and Michelle had proven indispensable. And let’s be real: Uncle Jesse and Aunt Becky were #CoupleGoals.
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Logan Huntzberger, Gilmore Girls
Image Credit: Everett Collection Yeah, we know: When Logan first arrived in Season 5, he was an ass. But throughout the last three seasons of Gilmore Girls‘ run — as well as its Year in the Life revival — Matt Czuchry’s endlessly charismatic character not only matured quite a bit himself, but played a crucial role in Rory’s character development. For better (saving the day at the Yale Daily News) or worse (agreeing to steal a yacht), Logan was ultimately synonymous with Rory’s college years and early adulthood… and all these years later, he’s still a worthy opponent in the ongoing Rory’s Best Boyfriend debate.
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Remy "Thirteen" Hadley, House
Image Credit: Everett Collection As far as we’re concerned, the OG diagnostics team consisting of Cameron, Chase and Foreman was the best diagnostics team. But if series creator David Shore hadn’t dismantled the fan-favorite trio at the end of Season 3, we wouldn’t have met the deceptive Thirteen. Her struggle to come to terms with her dire fate — she inherited the gene for Huntington’s Disease — resulted in some of the series’ best storytelling, and her absence for much of Seasons 7 and 8 was felt once Olivia Wilde left to pursue movies.
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Amanda Rollins, Law & Order: SVU
Image Credit: Courtesy of NBC The detective from Georgia joined the show in Season 13 and initially was an over-eager addition to the Special Victims Unit. But when Amanda settled in, she grew to be a more than capable member of the team, and (just as importantly) a confidant and friend for Benson. By the time Rollins’ friendship-turned-romance with detective-turned-assistant district attorney Sonny Carisi blossomed in Season 22, Kelli Giddish’s character felt like she’d been part of the unit since the start.
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Ben Linus, Lost
Image Credit: Everett Collection Henry Gale, we hardly knew ye. The rescued “hot air balloonist” was as quick to earn the 815-ers’ sympathy as he was to betray them, infiltrating their world before eventually revealing himself to be the leader of the mysterious Others. Arriving midway through Season 2, Michael Emerson’s mercurial character wound up appearing in half of the island mystery’s 121 episodes.
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Sue Ann Nivens, The Mary Tyler Moore Show
Image Credit: Everett Collection Adding a touch of acid to the CBS comedy’s successful recipe from Season 4 on, Emmy winner Betty White’s Happy Homemaker host stirred the pot with a never-ending series of come-ons and putdowns (aimed at WJM colleagues Lou Grant and Murray Slaughter, respectively). The fact that her baser instincts were hidden in plain sight under a sickly-sweet facade was just icing on the cake.
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B.J. Hunnicutt, M*A*S*H
Image Credit: Everett Collection When Wayne Rogers quit the Korean War war comedy shortly before Season 4 (stemming from his dissatisfaction with Capt. “Trapper” John McIntyre’s sidekick status), Mike Farrell seamlessly stepped in as Capt. B.J. Hunnicutt, who proved to be a perfect new still-sipping swamp-mate for Alan Alda’s Hawkeye. (Weeks later, Harry Morgan would show up as Col. Potter to fill a void left by McLean Stevenson’s Col. Blake, in another of the series’ A+ succession plans.)
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Christine Sullivan and Roz Russell, Night Court
Image Credit: Everett Collection (2) The early seasons of NBC’s courtroom comedy saw plenty of cast turnover, with several public defenders and bailiffs cycling in and out before Markie Post and Marsha Warfield took over as Christine and Roz in Seasons 3 and 4, respectively. Christine was an idealistic, maybe overly chipper defense attorney who sparred memorably with lecherous prosecutor Dan Fielding, and Roz brought a tough, no-B.S. energy to the courtroom as the new bailiff. With these two in place for the rest of the series’ run, Night Court finally settled on the core ensemble we know and love.
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Taylor Townsend, The O.C.
Image Credit: Everett Collection Autumn Reeser’s overachieving character joined the Fox soap in Season 3 as a foil for Summer, but it wasn’t until the following season, when the actress was promoted to series regular, that we really fell for Taylor and her quirky charms. As she became friends with Summer and started a delightful opposites-attract romance with Ryan, Taylor became an essential member of the core group, bringing much needed levity in the wake of Marissa’s death.
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Erin Hannon, The Office
Image Credit: NBC screenshot The cheerfully naïve receptionist played by Ellie Kemper had pretty big shoes to fill when she replaced Pam at Dunder Mifflin’s front desk in Season 5. She filled them beautifully, though, with Kemper bringing a zany new energy to the cast, and Erin’s relentlessly upbeat outlook did a lot to brighten up The Office‘s drab later seasons.
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Hook, Once Upon a Time
Image Credit: Courtesy of ABC The fantastical ABC drama was rife with princesses, queens, would-be saviors and sassy diner waitresses when it launched, but the early-Season 1 death of the sheriff/Huntsman (played by Jamie Dornan) pretty much left Josh Dallas (as Prince Charming) and Robert Caryle (as Mr. Gold/Rumple) to hold down the fort on the menfolk front. As such, Colin O’Donoghue’s Season 2 arrival as Killian Jones proved not only to “hook” female viewers but serve storylines for the remainder of the show’s seven-season run.
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Ben Wyatt and Chris Traeger, Parks and Recreation
Image Credit: Everett Collection Parks and Rec was already a pretty good sitcom, but it didn’t become truly great until Adam Scott and Rob Lowe joined the cast near the end of Season 2. Ben was a nerdy state auditor and Chris was his relentlessly cheerful colleague, and their arrival added all kinds of fun new dynamics to the Pawnee parks department, including a sweet romance between Ben and Leslie Knope. Swapping them in for the blah Mark Brendanawicz was definitely an upgrade.
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Sarah Reeves, Party of Five
Image Credit: Everett Collection The Fox drama centered around five orphaned siblings, but their significant others were just as important to the family drama as the Salingers. In particular, Jennifer Love Hewitt, who joined the show in Season 2, cemented her place in Bailey’s heart as his on-and-off high school girlfriend until Hewitt ultimately departed in Season 6 for her own short-lived spinoff Time of Your Life.
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Shaw, Person of Interest
Image Credit: Everett Collection Given the instrumental 1-2 punch that she and Amy Acker’s enigmatic Root would wind up delivering for much of the AI thriller’s run, it’s hard to believe that Sarah Shahi’s badass Sameen didn’t first appear until 16 episodes into Season 2.
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Mark and David Healy, Roseanne
Image Credit: Everett Collection Becky and Darlene’s high school sweethearts were introduced in Seasons 3 and 4, respectively, and remained fixtures for the duration of the series’ original nine-season run. Becky’s relationship with Mark was a source of great tension, as the straight-A student dropped out of high school and eloped with her dimwitted boyfriend — a decision that continues to haunt Becky on The Conners. And Darlene and David’s on-again/off-again relationship eventually played as pivotal a role on Roseanne as Roseanne and Dan’s marriage, which made it especially hard to accept that the former lovebirds didn’t live happily ever after once the sitcom resumed in 2018.
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Newman, Seinfeld
Image Credit: Everett Collection We actually didn’t say “Hello, Newman” to the obnoxious mailman played by Wayne Knight until Season 3 of the hit NBC sitcom (although his voice was heard in a Season 2 episode). He quickly became a standout, though, for his unearned bravado and unquenchable hatred for Jerry — and the feeling was mutual. He weaseled his way into the core foursome’s shenanigans so often, he practically became their fifth member… although Jerry would surely recoil at that suggestion.
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Anthony Marantino, Sex and the City
Image Credit: Courtesy of HBO Carrie’s gay bestie Stanford was a key part of HBO’s sex-com from the very beginning, but it wasn’t until Season 3 that Charlotte got her own companion in the form of fiery wedding planner Anthony, played by Mario Cantone. His blunt, borderline rude manner of speaking made him the perfect pal to (loudly) stick up for meek little Charlotte, and even after her wedding, he kept hanging around to give Charlotte brutally honest advice and a tightly toned shoulder to cry on.
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Butters Stotch, South Park
Image Credit: Everett Collection This endearingly gullible little guy was just an unnamed background character for South Park‘s first two seasons, but he finally got a name and a personality in the Season 3 episode “Two Guys Naked in a Hot Tub” — and he never looked back. Painfully naïve and often the butt of jokes, Butters won fans over with his unfailing optimism and love of Benningan’s, and he became an indispensable member of the South Park gang. He even got his own theme song!
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Max Mayfield, Stranger Things
Image Credit: Netflix screenshot When the skateboarding tomboy rolled into Hawkins in Season 2, she inadvertently brought with her a little tween angst (owing to pals Lucas Sinclair and Dustin Henderson’s crushes on her) and a lotta bullying (courtesy of stepbrother Billy Hargrove). But overall, Sadie Sink’s plucky heroine fit in with our young protagonists so well that she could have been the piece of the puzzle that we’d never realized had been missing.
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Castiel, Supernatural
Image Credit: Courtesy of The CW When Dean and Sam’s angel pal made his memorable debut in the Season 4 premiere, he introduced a whole new heavenly world of mythology to the series, making Misha Collins’ Castiel an essential player in the plot. And as his dynamic with the Winchester brothers expanded, the character became so rooted in the show that it’s difficult to imagine that there are seasons where Cas didn’t yet exist.
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Mr. Furley, Three's Company
Image Credit: Everett Collection Don Knotts had a big vacancy to fill when Norman Fell and Audra Lindley skedaddled to star in their own spinoff The Ropers. Moving into the apartment complex in Season 4, Mr. Furley tried to be a strict landlord with firm rules, but it didn’t take long for his feigned machismo and slow-witted reactions to deliver some serious belly laughs. While the Ropers were surely missed, Knotts’ bumbling, Barney Fife-like character was the next best thing, fitting in perfectly with the show’s surplus of comical misunderstandings and double entendres.
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Alcide Herveaux, True Blood
Image Credit: Courtesy of HBO Woof! Although the great debate over HBO’s supernatural drama centered around which of Sookie Stackhouse’s vampire suitors was her soulmate — Bill Compton or Eric Northman — the script was flipped in Season 3 with Joe Manganiello’s casting as an eventual leader of the pack… of werewolves. Alcide proved to be a formidable rival for Sookie’s fang club — and so popular that his death early in Season 7 left viewers howling.
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Negan, The Walking Dead
Image Credit: Courtesy of AMC Once the Saviors’ Chatty-Cathy leader took his first swing in Season 6’s finale, the AMC drama finally had a Big Bad who was scary enough to send us to pee-pee pants city simply by whistling. But Jeffrey Dean Morgan’s villainous character was more than a worthy opponent for Rick Grimes. Negan was also complex enough to navigate a once-unimaginable redemption arc to earn his own spinoff.
