How well do you know your neighbors, shop keepers, the old guy down the street with all the little mementos from around the world? If you haven't known them your whole life there's a chance they may be a badass.
Just as Badasses come in many different varieties, so do retired badasses. Some are happily retired from adventuring, sports, fighting, or whatever they used to do and are content to live a normal life in a normal little town, or even the simple life in Arcadia. Some have become shopkeepers who just do a little work to keep in touch with people and get by in their old age. Some get promoted within their organization to a Desk Jockey supervisory role. Often, they spend all their time tending a field. Some of them never really get into retirement because every time they start to settle into it they get jolted back out. Maybe they have a secret longing to get back into the game, (whatever it may be) or regrets about the past. Often they're perfectly happy in their retirement and are pointedly ignoring events of the outside world until the evil Mooks of whatever Big Bad that is looking to take over the world come in and wreck his shop, then laugh at him because, after all, what can an old man do about it? It doesn't take long for the asskickery to commence.
Their personalities often break down into two broad categories; some are Zen Survivor types who've made peace with their past and the fact that they are no longer The Hero, and now just want to get on with their life. Other times, bitter and cynical with age, they turn into a Nietzsche Wannabe after being put on the scrap heap of life.
One thing badasses of all types have in common is that they're magnets for trouble, and even in retirement this doesn't change. Occasionally these guys get pulled back into action because the Big Bad (or his men) know his reputation and come to make trouble. Other times it's because a young Arrogant Kung-Fu Guy wants to make a reputation by beating the old legend. Perhaps the most frequent case is that when the heroes are in trouble and need help to accomplish their goals, they will come to the Retired Badass either for physical help or advice about their quest, or because the retired badass is a past teacher, mentor, even father figure.
Exactly how the retiree in question will respond may vary. Sometimes they will come fully out of retirement to join up with the heroes and their party, sometimes they will just give some words of advice and/or an epiphany that the hero couldn't come up with on their own, (or teach the hero something specific, like the ever popular Dangerous Forbidden Technique) but often they're just as likely to simply fade back into retirement once the immediate situation has been resolved. Their help or advice is frequently a one-shot deal: sure they can point a hero in the right direction, but after that, (and wiping the floor with some disrespectful mooks like those mentioned above), don't look to them for further help. After all, it's a big world and they're getting too old or disillusioned to play hero. Let someone younger pick up that mantle and save the world while they get back to living off their pension. However, they are usually more than capable of a Let's Get Dangerous moment if needed. Expect him to have an Emergency Stash of money / weapons / IDs when needed.
Occasionally, a current hero will turn into The Knights Who Say Squee, much to their embarrassment of their fans, who treated what they thought was an insignificant elderly person with contempt.
Compare: The Obi-Wan, Older and Wiser, Old Master, Cool Old Guy, Old Superhero, Retired Gunfighter. Compare and contrast to Retired Monster and Retired Outlaw. A retired badass is one of the more common types of Heroic Neutral. Those that are willing to come entirely out of retirement to help a hero, (such as the Student and Master Team, for example) need to beware the Mentor Occupational Hazard. Might be the fate of a Kid Hero All Grown Up.
When someone's mission is to seek out a group of them and rouse them back into action, they're on a Retired Badass Roundup.
Hiko Seijuro, Kenshin's former mentor that he has been estranged from for a dozen years by the time Kenshin comes to him for help in the series (It doesn't help that he left against Hiko's wishes). Although Hiko is probably the most powerful character in the series, he is content to live away from people and make a living by creating pottery. After much persuading he helps Kenshin take yet another level in badass, and protects some of Kenshin's friends from a giant member of a Quirky Miniboss Squad (as well as helping the guy work his issues). Despite knowing about the threat of Big Bad Shishio, however, he gives no hint he had any intention of doing anything about it.
Nenji Kashiwazaki aka Okina, the former mentor of Kenshin's Worthy Opponent Aoshi, works along with other former ninja as the owner and manager of an inn. He still has contacts among spies in Kyoto that he uses to aid Kenshin. Aside from a fight with Aoshi, however, when he sees that his former pupil has gone a little too dark and edgy for his taste, he mostly stays on the sidelines, acting more as The Strategist and advisor from now on. (Although considering the HUGE wounds Aoshi inflicted on him, it's well justified. no wonder poor Misao, who saw Aoshi almost kill Okina, was more than a bit disturbed).
In a filler episode from the anime, it is revealed that a former first rate swordsman who fought Kenshin in the revolution now works as a children's teacher, having given up the sword. An old student who turned into an assassin tries to recruit him nonetheless.
That plot was recycled for the Ishinshishi e no Requiem movie, where one of the main characters (Takimi Shigure) was an ex-samurai who became a school retainer and the caretaker of his best friend's sister whom Kenshin killed in the war.
The title character himself is a Retired Badass, and would very much like to stay that way.
Ryuuken Ishida is adamantly in the Heroic Neutral column. For all that he can curbstomp his powerful and talented son Uryuu, Ryuuken just wants the spiritual world to leave him alone. His retirement is implied to be connected to the tragic death of his wife.
Isshin Kurosaki voluntarily gave up his powers a long time ago to save the life of the woman he eventually married but willingly comes back out of retirement once he regains his powers.
Andrei Rublev, Team Satomi's Zen-style coach from IGPX doesn't seem very Badass-y at first: portly, almost perpetually sullen, with an inflated ego way out of proportion to his apparent effect on the team. However, he's a prime example of this trope because of who he used to be: the legendary IGPX pilot known as Rocket G. In the second season, he dusts off his skills to act as a temporary replacement for Amy, who was injured in a race against newcomers Team White Snow, and steps onto the track twice more before fading back into his coach role.
Ginji from Black Lagoon also qualifies. Initially appearing as a big, imposing, but polite fellow selling masks at a festival, his identity as a retired assassin for the Yakuza was soon made apparent when Hotel Moscow tried muscling in on Yakuza territory.
Battle Butler Walter of Hellsing is retired from his former career as a top Hellsing agent, mostly doing standard butler duties and occasion bodyguard work for his boss. But when an attack by a pair of low rent vampires and their small army of ghouls overruns Hellsing headquarters he has a chance to show he can still live up his "Angel of Death" nickname, complete with a "What can an old man do" moment first.
Between that and all the other threats to Hellsing, England, having to show newcomers the ropes, and advising Action Girl Integra Hellsing, it's a wonder Walter gets any time off...
And don't forget he designs the weapons that Alucard and Seras uses!
Ilena from Claymore probably works for this (although she's spent more time actively hiding than living in peace, it IS in a cottage in the country).
Joseph Joestar in Part 3 of JoJo's Bizarre Adventure. It's worth noting that he looks quite a bit like Sean Connery in his later years, and Connery tends to play Retired Badass character quite a bit. Loses the "badass" part in Part 4 when his age finally catches up to him, although anyone who is willing to open a vein when an invisible baby falls into a lake so the blood can make her show up can't completely relinquish it.
Cologne from Ranma ˝ is a quintessential example of the trope. She has been shown to be the most formidable martial artist in the series, with abilities far surpassing anything the main characters can do (and quite possibly above Happosai's level.) Yet, she's perfectly content running the Cat Cafe and letting the weirdness erupt around her, occasionally providing nuggets of information and only rarely being an active participant herself.
Maria from Mai-Otome is a retired Otome who works as an administrator and Stern Teacher at Garderobe Academy, temporarily un-retiring when it comes time to take back her school near the end of the main series. Natsuki, Shizuru, Mai and the other Meisters are amazed to see her in action, and also by the fact that she used to be a hottie.
Thors from Vinland Saga, following the birth of his daughter. Unfortunately he wasn't allowed to stay retired.
Chef "Red-Leg" Zeff of One Piece was a great pirate in his prime who survived intact sailing on the Grand Line for over a year (outside the GL that's quite a feat). Even his "moment of retirement" had shades of Badass. Depending on whether you read the manga or watched the anime respectively, he either ate his own leg so a young Sanji could survive off the actual food, or cut it off to rescue a drowning Sanji. Even as a peg-legged old man, he still has the Stuff, kicking so hard it blew away bullets fired towards him. Though he prefers to let the youngsters handle things.
One Piece has quite a few retired badasses. One recent and very badass example would be Silvers Rayleigh, Gold Roger's former first mate. These days he runs a small business in Shabaody Archipelago, coating ships with a special substance, which enables travel to Fishman Island.
Dr. Kureha too. She's demonstrated that she can probably take all of the Drum Island baddies herself, despite being 139 years young, but is content to just watch. She even outright mentions it.
Dr. Kureha: If you guys can't handle it, I'll come save you.
Granny Chiyo from Naruto. First portrayed as a doddering, almost-senile old woman who wants nothing more to do with her village and it's politics, beyond berating the village elders of Sungakure for relying on Konoha instead of training to be more powerful themselves. Then she and a young Combat Medic with Super Strength, Sakura Haruno, make a formidable team up and defeat Sasori, Chiyo's own grandson/pupil and member of the Akatsuki — using puppets that were built by Chiyo herself, as well as better made and with more tricks/better builts than Sasori's own. Notable in that the aforementioned Sasori is one of the most powerful member of the Akatsuki, an organization exclusively composed of unbelievably badass rogue ninja who generally require a combination of multiple high-level protagonists and convenient plot devices to take down. Put in context; Pain, who killed half the supporting cast of the series and destroyed the hero's hometown single-handedly, basically just has the ability to manipulate six nearly-indestructible corpses at once and utilize powerful jutsu through them. Sasori could do this with a hundred corpse "dolls" at a time. Although Pain had the good sense not to tell his opponents all about how his powers worked. Then she brings Gaara back from the dead, not only pulling an Heroic Sacrifice for him, but atoning for having sealed the Shukaku in Gaara as a newborn, which is the reason why she left Sunagakure in the first place.
Genkai from YuYu Hakusho had been happily retired for years before she took Yusuke on as an apprentice and promptly got dragged right back into the crap she'd worked so hard to get out of.
Also Kuroko Sanada, Yusuke's predecessor as (the first) spiritual detective, who now lives happily on an estate with a husband and two kids. Although from time to time she (or one of her kids) has to kill a demon who dared to trespass.
Half the members of Ala Rubra in Mahou Sensei Negima! are retired badasses. The most prominent would probably be Eishun, Konoka's father. He's a master Shinmeiryu swordsman implied to be about on par with the likes of Jack Rakan or the Thousand Master, but the only arc he appeared in without being in a flashback he was petrified by a minor mook. Who turns out to be the Big Bad, and defeated Jack Rakan. So it doesn't make Eishun look that bad.
Miya, the woman who runs Izumo Inn in Sekirei is in fact Sekirei #1 (though not a "Sekirei" as such, presumably because she was already mature when the Sekirei were discovered), and apparently the most powerful of all (in a flashback, she takes out a battleship with a single swing of her sword!). For reasons that aren't clear, she's hellbent on preventing the protagonist from finding this out (his Sekirei, of course, all know. 2 of them fought alongside her, in fact.), to the point of subtly threatening people who try to reveal more than she wants them to.
Apparently she gave up fighting due to the influence of her late husband, the partner of Minaka (the man running the whole Sekirei game) who presumably either murdered her husband or had him murdered. When asked what she would have done if she'd been told about another character's intentions to kill Minaka, this is her reply◊..
Fujimaru "Falcon" Takagi appears to be this in Bloody Monday: Season Two, claiming to have not even touched a keyboard since the first season but this is just a facade to prevent his friends from getting involved again.
Nanoha herself during Magical Girl Lyrical Nanoha ViVid, though the existence of Force shows that she'll be back in action after two years. Einhart mistakes her for an ordinary housewife in Chapter 10, leading to lots of barely constrained snickering from the other cast members.
KariyaKagetoki. While he spends most of the series gardening and listening to reports of what's happening to the main characters, their exploits eventually coax him out of retirement...and that is is a very bad thing for Jin, Mugen, and Fuu.
Kira Yamato starts off like this in Gundam Seed Destiny. Though it's not long before circumstances get so dire that he decides step out of retirement. It helps that the Big Bad tried to assassinate his girlfriend.
The rest of the Three Ships Alliance is this seeing as they went into hiding following the end of the Bloody Valentine War except for the Kusanagi which is understandably protected by their lack of having to do a Heel-Face Turn and therefore become wanted criminals. Once back in action, they wipe the floor with everyone.
Cure Flower of HeartCatch Pretty Cure! comes out of retirement once to kick some major ass. Her fairy partner Coupe also qualifies seeing as how he appears several times to save the Pretty Cures and does so my kicking serious ass.
Gran'ma Ben and Lucius Down from the Bone comic book series.
In W.I.T.C.H., Hay Lin's grandma Yan Lin fits, as (when she as younger) she had her granddaughter's place in the Kandracar Five-Man Band.
Batman: The Dark Knight Returns. The entire thing was about Batman retiring, dealing with his retirement and returning to the job, despite problems with his age.
Also, Batman's majordomo Alfred. Several of his origins highlight his retired bad ass status. RAF, Special Forces... the job title he's retired from varies Depending on the Author, but they're all Badass military positions.
Done more straight in The Life and Times of Scrooge McDuck, which follows Scrooge's entire life until Donald and his nephews are introduced to his old self, having become a shadow of his former self. Thanks to having to take action against a new generation of Beagle Boys however, he gets an Adrenaline Makeover and returns a Badass (at least as much of a badass an 80 year old man can be.)
After multiple eventful tours in Vietnam, Frank Castle decided to stay home with his wife and children. Tragically, one bad day in the park gave him a new war to fight.
Subverted in Watchmen - a reader accustomed to this trope might expect Hollis Mason, the original Nite Owl, to fight off the street gang that breaks into his place with ease. This, to say the least, is not how it plays out.
In the director's cut of the film version, Mason does fight back, with the blows cutting to brief flashbacks of him landing punches on masked villains when he was in his prime, but in the end there's just too many thugs for him to take on at once. There's even a brief Hope Spot for him (and an Oh, Crap for the thug) right at the start, where he catches the first punch before laying out the thug.
Sam's Granny Ruth, from Sam & Max. She ran a Jail much like Alcatraz during the Cold War.
The Tramp, once something of a legendary figure among other dogs, is perfectly happy to live a lazy family life. Not that he can't be provoked into showing some of his skills every so often. Just as long as Lady doesn't find out.
The Musketeer and the Legionary of Batman's Club of Heroes; The Musketeer is probably the greatest swordsman to ever emerge from Europe, even years out of practice and with no real interest in fighting crime anymore. The Legionary, however, is another story, having fallen from grace dramatically and becoming a fat slob in his later years. However, when he is assaulted at the Club of Heroes reunion he manages to not only land a bone shattering backhanded blow on his assailant despite suffering from 17 stab wounds, he leaves a clue for the other heroes to both indicate the killer and ensure their safety. He may have gotten sloppy, but the Legionary once stood shoulder to shoulder with (and garnered respect from) freaking Batman; he is not going down without a fight.
The modern Justice Society of America series is about these coming out of retirement in order to train the next generations of heroes. It helps that most of them have slowed aging, thanks to exposure to energies in a battle in the 40s or through other means.
James "War Machine" Rhodes becomes this after Iron Man was thought to have been killed during OnslaughtCrisis Crossover. He started his own marine salvage business called "Rhodes Recovery". A mixture of his sister being killed by a powerful gang and his business going bankrupt due to his shady accountant force him out of retirement.
Paperinik, Donald Duck's superhero person, became this in the Bad Future shown in issue 34 of Paperinik New Adventures, having passed the last fifteen years in hiding because he was framed as a terrorist. He get back in the game when a chance to change the past arrives.
A dark example from Astro City: Flying Brick Supersonic is brought out of retirement by a nostalgic old friend, but proves to be a shadow of his former self. Thanks to a combination of senility and lack of practice leaving him unable to use the clever and silver-age-y tricks he preferred during his career, Supersonic is reduced to wailing on his enemy until it stays down, causing massive collateral damage in the process.
Steel Song is enjoying a quiet small town life at the start of the book. However, he is an ex-guard, has worked for many years as a bodyguard, becoming quite famous in the process and is the only alive non-griffon Blademaster in existance. When he's called out of retirement to lead the Dusk Guard, he amply demonstrates just why the Princesses have chosen him.
Downplayed in Lockout, where "retired" CIA-Operative Snow is helping out a buddy who ends up dead. Snow is framed, and to regain his freedom and clear his name he gets sucked into the movie's main plotline: rescuing the president's daughter. HOWEVER, Snow takes the job in order to achieve a secondary motive, so it's all just bluster and bullshit.
In The Dark Knight, Alfred reveals that he did some soldiering in Burma when he was a younger man. It's implied that he was special forces, probably the Regiment. 22 SAS. The original badass squad(ron).
The aging James T. Kirk, during the movie Star Trek II: The Wrath of Khan, was, to a limited extent, semi-retired and silently dreaming to once again captain the Enterprise. So he stole the ship in the next movie, earning him a demotion from admiral back down to captain again.
Juni retires in Spy Kids 2, so he is this at the start of the third movie.
Elastigirl and Mr. Incredible from the 2004 The Incredibles. For a while. She adapts pretty well, he's not so happy about it. Possibly also Edna, who is apparently doing ordinary fashion design with shows in Milan when Bob comes to see her. She leaps at the chance to design for "gods" again.
Anthony Hopkins' Zorro from the 1998 The Mask of Zorro is a borderline example, as he is the original Zorro that is captured for decades until training a new Zorro, his protégé Alejandro, years later. Straddles the line with an Older and Wiser mentor.
In Kung Fu Hustle, not only did they have five Retired Badasses living in the same slum, once they got involved with The Hero and his fight with the Axe Gang, the gang went and dug up their own Retired Badass to fight on their side. Better yet, some of these characters were played by actors who were big names in martial arts movies - in the 70s and 80s. The director called them out of retirement to be in this film, which I suppose would make them Meta Retired Badasses.
Everyone in RED. The acronym stands for "Retired and Extremely Dangerous".
The title character in Harry Brown is an ex-Royal Marine who has become a quiet, rather meek old man until his wife and best friend die. With nothing to lose and a group of thugs plaguing his council estate, he goes back to his old ways.
In The League of Extraordinary Gentlemen, Allan Quatermain is retired and living in Kenya, but is reluctantly summoned back to England to help prevent a world war. (This is a departure from the source material, in which he was located in an opium den somewhere in Asia.)
Secondhand Lions has three lead characters, two of whom fit this trope. Having fought in dozens of wars, they got old and tired before retiring to America. With their fortune came relatives and salesmen seeking money and one young boy who breaks them from their funk.
Epps had retired from the military between the second and third films. He comes out of retirement after It's Personal the Decepticons blow up the Autobot shuttle as it's leaving Earth, presumably killing them onboard.
Dutch, Simmons' assistant in the third film. He can hack into any system and disarm a Russian gangster pointing a shotgun at him without looking. When Simmons orders him to stand down, he almost sobs and says "I'm sorry, that was the old me!". This doubles as Actor Allusion to Alan Tudyk's role in Dollhouse.
Captain Freedom (Jesse Ventura) from The Running Man is a rare example of a villain who lived long enough to retire (imprisonment not being an issue in this case). His former employers try to coax him out of retirement to kill Ben Richards (Arnold Schwarzenegger), but he won't have any of it, not because he fears Richards, but because...
Captain Freedom: I was killing guys like this ten years ago with my bare hands! I'm not going for any of these tricks!
Done with hilariously campy style in Surf Nazis Must Die. A man that would be the hero in a normal action movie (the middle-aged black guy) is murdered by a group of self-styled Surf Nazis. Cue his aged mother to leave the retirement home and curb stomp the bastards.
In Bubba Ho-Tep, the two heroes claim to be Elvis and JFK, having retired into anonymity.
Joe Colton from G.I. Joe: Retaliation. The last scene of the initial trailer features Colton kicking ass by shooting at Cobra mooks with an assault rifle while in the bed of a fishtailing El Camino. Considering he's played by Bruce Willis, this comes at no surprise.
Stacker Pentecost was previously the co-pilot for Coyote Tango, before he quit after his cancer worsened and was pulled from flight status by his doctors. And as seen in the trailers, he resumed piloting after one pilot from Striker Eureka is injured.
Raleigh retired after the death of his brother, only to be called back to duty by Penetcost when they are in desperate need for pilots.
In X-Men Origins: Wolverine, Fred Dukes and John Wraith become a boxer and his manager respectively, after Team X disbands.
In Dracula Untold, Vlad wants nothing to do with his past as the "Lord Impaler." He doesn't succeed in ignoring that part of himself.
David Gemmell's Druss the Legend ... in his forties and already retired when he fought at Skeln Pass and in his sixties when he came out of retirement again to fight at Dros Delnoch in Legend. Death offers him another twenty years' life, or a glorious death, at the beginning of the novel...
Averted in Discworld with Cohen the Barbarian. Despite age, wealth, taking over an empire, and plenty of other reason to retire, Cohen and his Silver Horde comrades utterly refuse to retire. Even after their deaths in a Rage Against the Heavens arc, their spirits refuse an afterlife that seems to be everything they want.
While Cohen averted the trope, it was played straight in The Last Hero with Vena.
And while we're talking about Discworld, how is it that no-one has mentioned the main storyline in Reaper Man, where Deathis forced into retirement.
Sam Vimes intended to retire when he got married (and his wife gave him half the city as a wedding present). As he was having a really bad day at the office, and did retire...for about three hours. Then he realized he had to be himself and went back to work.
The badass who refuses to retire is played straight with Ser Barristan Selmy in A Songof Iceand Fire, who at the age of sixty-something is forced into retirement against his will and is so annoyed by it that he kills two heavily-armed men half his age sent to arrest him before crossing half the planet to join forces with a rival ruler, in whose service he later swims through a foul sewer into the heart of a heavily-fortified city to open the gates from inside.
Killing the two armed men was incidental, one might note; he'd already sneered at the collective swordsmanship of his own elite guard, saying he could tear through all four of them present without difficulty. Part of the reason he's such a badass is because he's more or less The Last of His Kind. In the Kingsguard, Selmy served with and was trained by luminaries like the Lewyn Martell, and Arthur Dayne, the Sword of the Morning — men that he claims were twice the knight he was.
Although in that particular case he was probably not referring to their martial abilities(or at least not exclusively) but to their character.
In To Kill a Mockingbird the children of mild mannered lawyer Atticus Finch were unaware of his badass marksmanship, until a dangerous mad dog wanders into town and someone needs to be able to safely put it down.
In G. Gordon Liddy's The Monkey Handlers, Michael Stone is a lawyer by profession...and a former SEAL. He keeps "the tools of his former trade closed up in a trunk" but before he opens the trunk and averts an international terrorist plot, he warms up by kicking a motorcycle gang's ass in a bar.
In Dragonlance many of the characters that survived the first set of books, like Caramon Majere, fell into this. Few of them enjoyed long or peaceful retirements...
Considering that after Legends, Caramon retires for 30 years, has one last adventure, then dies another 30 years later at the age of 90, and most of the other heroes to retire for 30 years as well.
Stephen King's "Apt Pupil" focuses on a Nazi general who's killed thousands of people, escapes to America and lives a quiet life in a small town.
Rather common in fantasy fiction. Many fantasy authors will return to the same setting again and again, progressing the time line, cranking out more novels, and retiring earlier heroes to give newer generations their own chance to shine. And it's particularly common in novels franchised from games like Dungeons & Dragons or Warhammer 40K, where you'll have multiple authors all progressing the plot in the one setting. Sometimes it gets to the stage where you can't move for kindly old priests, world-weary old nobles, and rough-around-the-edges old innkeepers who were asskicking adventurers five or six books ago. And if the new crop of heroes ever needs a seasoned adventuring veteran to show them the ropes and give them a hook to connect with an existing storyline, they can't swing a cat without hitting at least one gruff mysterious stranger who turns out to be the famous heroic whatsisname in the flesh.
This is cited as one of the reasons Forgotten Realms was moved forward a good century! Drizzt and Elminster are just about the only two still around, and they're both very, very busy.
Coll from the Chronicles of Prydain. Taran is quite surprised to learn his bald, peace-loving, pig-tending father figure is not only considered a hero, but responsible for rescuing a certain pig from the Big Bad's lair. (It was a very special pig.)
Aral Vorkosigan hasn't retired; he's physically unable to. That said, he has gone from being Prime Minister and an active voice in the Council of Counts to the Viceroy of Sergyar, with Miles taking over the Council duties. With Aral, that's as close as he'll get.
Barrayaran Armsmen tend to be this. No Count is allowed more then twenty personal musclemen for understandable reasons. Therefore these tend to be picks of the best soldiers, cops, spies or whatever that can be found in a whole planet that have done enough service to prove themselves worthy to decorate a petty aristocrat's court.
Sammy's friend Hudson in the Sammy Keyes books. Nobody knows if he worked for the CIA or the NSA or what, but he knows stuff like safecracking and cryptography. Or maybe he's just a Cool Old Guy.
Ciaphas Cain(HERO OF THE IMPERIUM) is ostensibly retired in Cain's Last Stand, though that does little to slow him down when the hordes of Chaos come calling to the sleepy little planet he's spending the rest of his days on.
He wants to be this, but that darn heroic reputation of his means he keeps getting called back into service, seemingly being killed in action, only to reappear and save the day. It got to the point where the Munitorum just considers him permanently alive despite his now being dead and buried.
Just for added reference, Cain managed to actually live to retirement. In the Warhammer universe.
The Novel Path of Fury starts out giving the operational history of the main character, just before dropping her into retirement on a farming colony for a dozen years. That's when she becomes not so retired.
Kvothe from The Name of the Wind became the world's most famous hero and retired long before he turned 30. Now he runs an inn. But probably not for long.
In The Wheel of Time Rand thinks his father Tam (later revealed as his adopted father) is a simple farmer whose handiness with a bow is simply down to a lifetime of hunting and hard outdoor work. Naturally it turns out his father was a badass warrior and infamous soldier, the second-in-command of the elite Illianer Companions and a blademaster who won great distinction in four or five major wars. Tam is forced out of retirement in Book 4 when Rand's home village comes under attack by hostile forces and by Book 11 is leading armies into battle again. Tam's badassery is slightly undone by the fact it took him eleven books and 22 years of in-universe time to work out that Rand is the Dragon Reborn (although some fans suggest he's been living in denial instead).
In one of the more mind-boggling examples, the Malazan Bookofthe Fallen we hear rumours of the 'old guard' loyal to the former Emperor who are lying low and waiting for a chance to strike back against the Empress. This plan reaches fruition in Return of the Crimson Guard, when literally an entire army of retired badasses (including many characters who had previously been encountered in other books and merely thought of as fishermen, farmers or guys living by themselves in some random tower by the protagonists) re-emerges to take some names and dish out some pain. In addition, there are a whole other bunch of retired badasses who arrive to fight on the side of the Empress. Seriously, this novel is this trope made manifest.
In Malazan it is not uncommon for dead retired badasses to rejoin the fray when needed.
The book Toll the Hounds almost goes into meta overload by having a bunch of badasses from the first three books in the series having literally retired to run an inn but are then called back into action again.
The heroine of Patricia C. Wrede's Caught In Crystal, a middle-aged innkeeper with two young children, is a retired swordswoman. She's dragged out of retirement when both her former employers and their enemies come looking for information about her last disastrous mission.
Robin Hobb's Tawny Man Trilogy starts with the main character being called back from his retirement from being an assassin, a spy and king's man, to serve and teach the new generation.
Kit Carson of Time Scout was forced into retirement by math. If he had continued to work, he would have died. Full stop. (To clarify, Kit's job was to scout time portals which could lead anywhere in history...but if they led into a point in time where Kit had already visited, he would immediately die. Eventually the odds got to be too bad even for him, and he gave it up.)
In the Belisarius Series Valentinian and Anastasius are last seen enlisting in the bodyguard of the Indian Empress Shakuntala, not to mention becoming sons-in-law of her chief counselor providing one of the best retirement packages available in the early Medieval World.
The Hunger Games: Once the war is over both Katniss and Peeta withdraw to District 12 and spend the rest of their lives in as much peace as they can find.
Prudence 'Roo' Jones starts Hurricane Fever having retired from the Caribbean Intelligence Agency and devoting himself to his boat and raising his nephew Delroy, until a message from a dead friend pulls him into One Last Job.
Christopher Henderson in 24, though a dark take since once Jack attempts to coax him out of retirement, it's revealed that he had already come out of retirement, did a Face-Heel Turn and was now a Dragon for the season's Big Bad.
Jack himself attempts to retire twice FOUR TIMES. The first time is following the first season. Jack is not retired in the true sense and listed as inactive. This is mainly due to the breakdown of his relationship with Kim, as well as suicidal thoughts following the big twist at the end of the season. Even so he's pretty quick to tell people he doesn't work for CTU anymore. Next is between seasons three and four, where he opts for a desk job in the Department of Defense. The third time is between seasons six and seven where he chooses simply not to come back to the United States. Obviously, this doesn't quite work out. As of Day 8, Jack is FINALLY truly retired from government work. He even tells someone this in the trailer for the season. He's living peacefully in New York City with Kim and his grandchild (guess this means you can add Retired Badass as well). No DoD desk job, no running from China and no trip to Africa. Needless to say since this is 24 it's not going to last long. Near the end of said trailer cue Dramatic Gun Cock and typical Crowning Musicof Awesome that goes with nearly everything 24 related.
President of Awesome David Palmer. After some rather unfortunate business in Season 3, he decided not to run for re-election and left political life. Come Season 4, and the current President, the weakly Charles Logan, decides that he needs somebody with balls to save America from mass nuking. One phone call later and President Palmer is back in the saddle (much to the annoyance of the actual Republican cabinet). Rule of Cool? Yes, but who cares?
Shepherd Book of Firefly fame is a relatively kindly old preacher whose mission in life is to guide the flock he's found on the good ship Serenity. Sometimes, said flock gets in trouble, and when that happens, the same kindly old preacher starts blasting men in the knees, knocking a cop senseless with his bare hands, and slicing apart battle droids with a giant curved machete.
Jack O'Neill begins Stargate SG-1 in retirement, but doesn't stay that way long once Apophis comes to town. SG-1's Reasonable Authority Figure, General Hammond, had also planned on retiring before the Stargate mission began, though he wasn't retired yet...and didn't retire for many years afterward, as he was having too much goddamn fun.
Sam Axe in Burn Notice. He's a former... something or other (it's not explicitly mentioned what he was) Navy SEAL Commander with buddies in seemingly every major US Agency. At the beginning of the show, he was making a living mooching off retired women in Miami. When his friend Michael comes back to town, however, he proves himself to be just as Badass as he ever was.
Lampshaded in "Friends Like These" when the supposedly bad guy Sam's interrogating is Serbian intelligence. He proceeds to try and psych Sam out by asking him what he used to do before he was an "errand boy" and figures out Sam is ex-military. He insults the SEALs to bait Sam into coming closer, then knocks Sam down and disarms him.
Milovan: Navy SEALs? Little girls! You've gone soft! How stupid are you? * goes to fire, and the gun clicks uselessly*
Sam: * drawing a second gun and getting up* Not stupid enough to let you near a loaded gun. Now sit down. * fires an inch from Milovan's foot* Please.
It doesn't take any great leap of the imagination to see the First Doctor companion Ian Chesterton as belonging here. People often remark on the incongruity of a Secondary School science teacher apparently being able to nonchalontly kick various kinds of arse. Glance at a calendar and do some mental arithmetic, and you'll realise that, as a man in his late-30's/early-40's in 1963, Ian probably had quite an important event tucked away in his backstory. You can bet that not even the mental kids acted up in his class.
The Curator, the caretaker of the National Gallery, who looks suspiciously like an older version of the Fourth Doctor. His Cryptic Conversation with the Eleventh Doctor in "The Day of the Doctor" suggests that he's a future incarnation of the Doctor, who has since retired from saving the universe and now spends his retirement between working as a humble museum worker and revisiting a few of his old faces (but only the favourites!).
Buffy the Vampire Slayer's Rupert Giles, the bookish demon expert of the group, has a hinted-at past as rebellious badass "Ripper", but now all he does is sit around in the library and help out a few kids. Except for, you know, when he charged into the Big Bad's headquarters, no support, completely alone, with a flaming baseball bat. And kicked vampire ass.
Claude Rains, the Invisible Man from Heroes is a variant of this. Subverted somewhat, as he's less of a Retired Badass and more of a Screw-This-I'm-Outta-Here Badass.
NCIS: Mike Franks, Gibbs's mentor, is this. Implied that he retired due to the Khobar Towers bombing, then he went to live in a beach at Mexico. Whenever a situation arises that has him come back to the United States, however, he turns to be still quite good at what he used to do, and during at least two cases he got and trailed leads before Gibbs did, in one of these occasions taking the episode's villain himself. He also sneaked by and terminated Jenny Sheppard's killers and was instrumental in a case holding some keys to Gibb's past.
General Williams in "Desert Son", former Commandant of the Marine Corps and Medal of Honor recipient. Even as a retiree, he still warrants his own helicopter transport and honor guard.
The trio of retired underwater demolition divers (one of them played by Ernest Borgnine), in "Yesterday’s Heroes", whom despite living at a retirement home in Florida decides to take on a drug dealer.
Admiral Boone (Terry O'Quinn), the wingman of Harm's dad, is recalled to active duty in season 7.
Tommy from Power Rangers has tried to become this several times, but he keeps getting chosen for new powers and duties. He probably would have stayed retired, if his initial idea of "peaceful retirement" hadn't been "Mad Scientist experimenting with oversized cyborg dinosaurs and magic rocks on a private island". By the end of Power Rangers Dino Thunder, however, he had to take care of the aftermath of that little booboo, and was in the much more relaxing career of "high school science teacher", which, while stressful, is not apocalyptically so.
Some of the mentors qualify as well. Samurai Sentai Shinkenger features Ji, who's old enough to be a Badass Grandfather and is mainly in charge of the day-to-day operations of Shiba manor, but he is able to take on a horde of Nanashi using a naginata and a katana, and once killed one barehanded.
While not a conventional example, Hal from Malcolm in the Middle can take any one of his sons in a fight and leave them gasping for air in seconds (his words). Now if you've ever seen Francis and/or Reese cutloose, you know this sweet, unassuming guy has got to be like seven kinds of Badass.
Although we haven't seen him cut loose it's implied that Zeke from Parenthood is this.
Samuel Colt of Supernatural, as shown in one of the Time Travel episodes. When two demons come knocking, he tells them quite politely to walk away, he's retired. When they refuse, he kills both of them in the span of two seconds, and only laments that they knocked over his bottle of whiskey.
Bobby could be seen as semi-retired, fielding phone calls and doing research, but is in fact a crafty, tough old bastard with an encyclopedic knowledge of the occult.
On Teen Wolf, Dr. Deaton. He repeatedly states HE'S RETIRED, but the end of season two sees him back in action going after Gerard.
In BIONICLE, Turaga are Toa who retired by sacrificing their powers to save Matoran. The only ones we've seen this happen to did it as self-sacrifice (and for all we know that may be the only way to do it), so they tend to be of the zen variant.
Rahaga. Formerly Toa Hagah, but Roodaka ambushed and forcibly retired them from being Toa. That is, until several thousand years later, the Toa Nuva forced Roodaka to turn them back.
Large Hat Gentleman in The duel with sabres by Caran d'Ache (Emmanuel Poiré). Page one◊, page two◊. "Not so bad for an old 'un", indeed.
Sometimes found in Dungeons & Dragons either as something that happens during the course of the story, or as a small event when, say, an innkeeper pulls the mace down off his wall to help the heroes and show that it's not just ornamental. Having the 'adventure inn' be run by a retired high-level adventurer is something of an old cliché in the game.
At least prior to the recent Reset Button, it seems the Forgotten Realms is stuffed full of Retired Badass characters... and then stuffed some more.
Whole areas populated by these. One example would be City of Ravens Bluffnote still available in old free downloads — during the city's raise as a major trade port its populace grew from about 17000 resident and 3000 adventuring to about 30000 settled plus 10000 adventurers — fair number being high-level, with the heads of local Wizards Guild equal in power to less powerful among the rulers of magocracies, and so on. Dales are different, but Dalesfolk tend to be very tough. In both cases, locals who live to tell interesting tales and outside adventurers who like the atmosphere end up settling there.
4e got most of those retired badasses dead. Elminster and Drizzt are just about the only two, and both are very busy. (Elminster is VERY retired... he doesn't leave his hut!)
Truthfully, Elminster always claimed he was retired, but the thing is, with wizards, being "retired" isn't always that straightforward. (Folks in the Realms often suspect that a wizard who makes this claim is up to something, and they're usually right.)
In the first game, Solid Snake had retired to the Alaskan wilderness to try to get away from his past before being forced back into service. Technically, he had semi-retired prior to the beginning of Metal Gear 2: Solid Snake, as well. His retirement is usually explained as disillusionment after the many revelations of the first and second games, and it was usually with the blessing of his parent agency (FOXHOUND)... until they needed him again. In Metal Gear Solid, he was understandably upset to be pulled out of retirement, which he entered at only about twenty-seven or twenty-eight.
There's also Col. Roy Campbell, who isn't a Colonel anymore during the first Metal Gear Solid, but Snake continues to respect him and refer to him as such despite Campbell's objections.
This can also be said of everyone who was part of the Cobra Unit in WWII. No one knows what happened to them after the war, (With the exception of The Fury, who got crisped in space.) but The Boss brings them all back together.
Quercus Alba of Ace Attorney Investigations was given an ambassadorial position after becoming a highly decorated general in the Cohdopian military. He still won a knife fight with a man half his age, then arrange a complex plot to smuggle his corpse into the Bahbalese embassy to make it look like he was killed somewhere completely different with a different weapon.
Phoenix Wright is not retired so much as disgraced and disbarred, but he plays this role for young rookie Apollo in Apollo Justice: Ace Attorney. At the end of the game, with his name cleared, he comes out of retirement.
Laike from Lunar: Silver Star Story is still an adventurer despite being retired from heroism. He just does it for kicks.
In the Kingdom Hearts series, Yen Sid used to be a Keyblade master on par with Eraqus and Xehanort. But he retired and passed his knowledge onto Mickey, which turned out well.
Garcia from Fire Emblem: The Sacred Stones retired from Renais's army when his wife died. He was talked into coming out of retirement by his son Ross after helping Eirika's army ward off bandits who were attacking their village.
Jeigan from Fire Emblem Akaneia retires from the battlefield inbetween the two games and becomes the hero's non-playable strategist. At the end of the saga, he retires from an army.
Citan from Xenogears: When you first meet him, he is just a simple country doctor with a hot wife and precocious daughter. Then it turns out that he was one of Solaris's elite Elements and is one of the most powerful playable characters. Especially on disc 2, where he's retrieved his sword. As a bare-handed fighter he was already tough. As a master of iaijutsu, he's a virtual one-man army.
Muramasa from the Xbox remake of Ninja Gaiden, an elderly shopkeeper, shows himself in the second game to be quite the fighter.
Red in Pokémon Gold and Silver/Crystal is one; despite being only 14 years old, he has one of the most powerful Pokemon team in the history of the series, and has the highest-level Pokemon that any NPC trainer has.
Steven Stone, the League Champion of Ruby and Sapphire, steps down from his position in Emerald, letting Wallace take his position instead, while Wallace's mentor Juan takes over things as the Sootopolis Gym Leader. You have the option of hunting down Steven in Meteor Falls and challenging him to battle; his Pokemon are even stronger than his team as Champion.
Professor Oak was intended to fight the player at some point in development of the first generation of games, as his team still exists in the game data (and can be fought with codes or glitches). He would have had a team of the highest level Pokemon in the game (tied with Mewtwo at Lv. 70) and be one of two trainers to have a decent team setup.
And since Oak is permitted to enter the hall of fame it is subtly implied he was once a champion in the canon storyline too.
In Pokémon Special, Oak enters the Pokemon League finals as "Dr. O". He defeats Blue fairly easily. When Green tells him that he'll have to face either Green or Red in the finals, Oak forfeits, saying he already won a championship and he doesn't need another.
Deconstructed in Pokémon Black and White. Alder gets called out of retirement to put a stop to N's ascent to power, but he's badly out of practice, and the player character arrives as N finishes mopping the floor with him. Reconstructed post-game when Alder starts training again and becomes a Bonus Boss.
Advance Wars 2 has Hachi and Sensei. The former is the game's shopkeeper most of the time, except he also happens to be one of the most powerful playable characters. As for Sensei, his opponent during his first appearance shrugged him off as just an old man. That is until this person realizes Sensei's real identity and past reputation as a C.O., at which point he becomes positively terrified.
Bill from Left 4 Dead. A former (so technically retired) Green Beret who served two tours in Vietnam.
Buddy Cheque, Abner Dubbleplay, and Erik Stream from Backyard Sports. Barry Dejay seems like this, but he's not officially retired; he just has a broken ankle (and is a Small Name, Big Ego rather than a badass).
Mass Effect 2 has Dr. Mordin Solus, an old note Technically, he is in his early thirties, but given the salarian short life span it makes him a seasoned adult salarian doctor who set up a free clinic in the slums of a space-borne Wretched Hive so he could spent his final years helping people. He is also a former black ops science specialist who's very handy with a submachine gun, casually murders mercenaries who try to shake his clinic down and hangs their corpses outside as a warning, and willingly enlists on a suicide mission to stop the Collectors and their Reaper masters.
A more minor character, a krogan known only as "the Patriarch", can be found serving as The Dragon to the local crime boss in Afterlife, on Omega. Once upon a time, it was he who ran the planet, until a young asari named Aria came along and overthrew him, only leaving him alive as a symbol of what she was capable of. It's possible through a sidequest to bring him indirectly out of retirement; Aria wants him to hide from some assassins, but he can be persuaded to allow Shepard to kill them in his name, regaining some of his Badass status.
Ford Cruller from Psychonauts is retired, due mainly to a past battle shattering his mind into several personalities. This problem is remedied by the presence of psiantium, leading to a rather dramatic entrance during Sasha and Milla's battle with Oleander.
Arcanum: Of Steamworks and Magick Obscura has an interesting example. Late game, you run into the elven mage Nasrudin, chilling on an uncharted island, after being thought dead for lord knows how many years. What's particularly shocking, however, is that the entire plot up until this point has lead you to believe that you're the living one, the reincarnation of Nasrudin..
William Thorndop, the firearms master is a former highwayman who gave up his violent profession and decided to spent the rest of his life as an Order of Halcyon monk.
In Far Cry 2 Hakim and Iosip (Albanian Badass Grandpa) are retired from their respective nation's armies, but they both still kick ass. And in the first game, you're a retired special forces type (ex-CIA?) until the bad guys blow up your boat. That was a mistake.
World of Warcraft has several examples. Most notably Tirion Fordring, who players first meet as a humble small-holder in the Eastern Plaguelands. After the death of his son Taelan he reveals himself as a powerful Paladin and goes on to play a major role in the Wrath of the Lich King expansion.
His Worthy Opponent Eitrigg is a retired orc warrior who ran into him by chance. After some mutual life-saving, he rejoins the Horde as an advisor to help them learn the pre-corruption ways.
Landon Ricketts in Red Dead Redemption, a former American Wild West gunslinger who retired to Mexico, where he serves as an unofficial lawman when the need arises, but spends most of his time relaxing and playing poker.
Admiral Bobbery in Paper Mario: The Thousand-Year Door. A tough sailor who sailed the world and such when younger, he comes straight out retirement after Mario persuades him that they need a captain for the voyage to Keelhaul Key, then joins his party for the rest of the game slightly later.
"Reverend" Ray McCall in the first Call of Juarez. A former gunslinger, he slaughtered his way across the West before pulling a Heel-Faith Turn after murdering his preacher brother William. Then his other brother is killed, he thinks his half-Mexican nephew is the culprit, and he immediately digs up his old longcoat and revolvers for another blood bath.
Fallout: New Vegas has the Enclave Remnants, former members of the fascist Enclave army. The Courier, with the help of Arcade Gannon can rile them back into action for the final battle, where they drop in from Vertibirds (helicopters) in full Powered Armor with a variety of deadly weapons in which they show why the Enclave should be feared to this very day.
In Assassin's Creed: Revelations, Ezio leaves the Brotherhood to settle down with Sofia at the end of the game. Embers picks up more than a decade after this and he's still able to keep up with Shao Jun. She's 46 years Ezio's junior, too.
Bain in Payday The Heist used to do heists back in his day. Now he serves as the team's eyes and ears during heists when it comes to police activity.
By Call of Duty: Black Ops 2, Frank Woods is this. Well into his 90s, he is living in seclusion due to the large amount of secret information he's been privvy to from his combat days. However, he does share his experience with the son of the previous game's protagonist, describing the missions he worked on with Alex Mason.
In Icewind DaleII, the origin of the Holy Avenger Cera Sumat involved one of these. Long ago, an old paladin long since retired heard of six powerful villains called the Lost Followers ravaging the land. Taking up his sword once more, the paladin singlehandedly tracked down and defeated them all. The weapon description states that Cera Sumat was once a simple iron sword, but the courage and faith of the paladin made it something more.
Jolee Bindo of Knights of the Old Republic is an ex-Jedi hermit who crash-landed on Kashyyyk twenty years ago and never put much effort in trying to leave thanks to being quite disillusioned with the Jedi and the galaxy at large. (Granted, the forest floor is so dangerous that it's a semi-retirement at best.) He joins your party because he doesn't have much else to do and because you're actually Revan.
The Jedi Exile in the second game, a General in Revan's army during the Mandalorian Wars, who after detonating the super-weapon that devastated Malachor V and becoming severed from the Force, willingly accepted banishment from the Jedi Order and spent ten years wandering the Outer Rim. Part of their return to action is to discover why they've regained their Force abilities, find out who is trying to kill them and prevent a Humanoid Abomination from leaving planets devoid of life.
The Getter Team in Shin Super Robot Wars. They act as mentors for the protagonists' group and join up with Shin Getter late in the game.
In Sword of the Stars: The Pit the Marine character is technically an ex-Marine, a former SolForce man retired to the planet the game's set on.
Shiné and Shaedo in NewRem Comics. Both characters had played major parts in saving the world, the former even having at one point been made the world's goddess, before moving on to lives of internet-trolling and video-game playing, respectively.
In Bruno the Bandit, the protagonist's mother Eunyce is eventually revealed to be one of these. Before that, she's entirely retired; afterward, she comes out of retirement more or less permanently, ready to use her skills whenever necessary.
Old Man Death, who ran with the Jägers in his youth and Never. Lost.A.Fight. After being "ravished by a wild princess" he married her, gave up his old life and opened a deli. However, he can still hold his own in a fight with a science-magically modified super-soldier.
Carson von Mekkhan, Seneschal to Bill and Barry Heterodyne, also rode with the Jägers in his youth, an occupation described as something for people who liked to drink and fight and mess people up, and didn't care if they lived or died. When we first encounter him, he is sitting in a rocking chair and discussing dinner plans with his granddaughter. He is still badass enough to go toe-to-toe with the Castle and win regularly.
Even In Arcadia has Master Odai, an old Fae who has secluded himself off in the forest. He's a retired Emerged, the most powerful type of known mage.
The seventy-something headmistress Elizabeth Carson. When Syndicate dropships and the unstoppable cyborg Assassin Deathlist invade her school, the gloves come off. Oh, she turns out to be Lady Astarte, possibly the greatest superheroine still around.
Also Dr. Yablonsky, one of the Powers Lab teachers, who has a cybernetic arm and leg. One of the character thinks he teaches the way Batman faces down thugs.
The end of Red vs. Blue Season 10 reveals that Butch Flowers, the Blues' deceased captain, was once Agent Florida and fought alongside the other Freelancers. It's not technically retirement, since he still answered to the Director, but his new job was much less intense.
The Plumber Knight Returns: Mario has been retired for twenty years, having been living under the assumed name of Michael Camborelli. The series depicts him coming back out of retirement to fight off a street gang known as the Goombas.
Avatar: The Last Airbender: Jeong Jeong is a former admiral of the Fire Nation who, disillusioned with the war and killing, deserted the navy, turned into something of a pacifist, (and not the technical kind either), and soon had a group of followers with no apparent goal other than to keep from getting caught or killed until Aang showed up. Jeong Jeong reluctantly taught him some rudimentary firebending, but disappeared at the end of the episode and did not return...until the finale.
Iroh might also count as a temporary example. Although not really active anyway through the first two seasons, he is genuinely willing to chuck all other concerns to run a tea house in Ba Sing Se.
Piandao is similar to Jeong Jeong, minus the pacificism and the bending. It's All There in the Manual that after he left the military for similar reasons he wandered around the world and studied under several masters before moving to his house. Then the Fire Nation sent one hundred soldiers, and he beat them all himself. After that they left him alone.
It's worth noting that all of the above are, along with Pakku and Bumi, revealed to be members of the Order of the White Lotus, which is more or less a secret society of retired badasses.
On a very different note, Hama, The Puppet-Master. She is still a formidable opponent at least into her eighties, and when you see how many Fire Nation soldiers they ended up sending to capture her and her alone. There must have been a reason for them sending quite that many troops.
Bruce Wayne does much the same in Batman Beyond, where he serves as a mentor to a new young Batman... although he also proves in a few scenes from the show that he can still kick ass, especially in the first episode with a gang called The Jokerz who assume that such an old man is harmless...
In Futurama: after taking up an interest in cooking, Bender finds himself a retired cook/mentor in Helmut Spargle, who lives just long enough to attempt to give Bender a lesson or two, (despite Bender's literal lack of taste), and a secret ingredient. With the confidence instilled by Spargle and the secret ingredient, Bender wins an Iron Chef style cook-off with famous cook Elzar. The stock twist comes when the Professor does an analysis on the secret ingredient, revealing it to be nothing but water... laced with LSD.
Yan Lin in W.I.T.C.H, as well as her companions in the former Five-Man Band (Halinor, Katma and Cassidy). When Nerissa restores their youth and powers and brainwashes them in the TV series, holy CRAP, the girls are in quite the trouble.
Wylie Burp in An American Tail: Fievel Goes West was formerly a legendary sheriff but when Fievel meets him he's a drunken shell of his former self, that is until he is given the task of training Tiger to be his successor.
The Chief in T.U.F.F. Puppy used to be T.U.F.F.'s top agent and able to take out a legion of villains singelhandedly. He comes out of retirement in one episode to catch the Chameleon with Dudley. While things don't go very well at first, after some encouragement from Dudley, he shows he's still got enough Badass in him to get them out of a jam, then beat the stuffing out of the Chameleon.
In Hey Arnold!, Grandpa Phil, notorious for his tall tales, claims to have beaten Hitler in a fistfight in WWII. He quickly takes this back... only to reveal on a strikingly serious note that he did beat up Goebbels.
Billy from Adventure Time. He was Ooo's previous greatest hero before Finn, who idolized him. Among his exploits, he killed an Evil Ocean by punching it, rescued a princess from the evil Fire Count, and most impressively, imprisonedthe Lich in amber in order to save the entire world. How does that get even more Badass? He imprisoned the Lich by pummeling him into the tree! He retired due to finding the fight against evil pointless since more always showed up. In the end, Finn and Jake convince him that fighting evil, while not a permanent solution, still helps protect people, implying he might come out of retirement.
Princess Celestia and Princess Luna from My Little Pony: Friendship Is Magic. They were the original wielders of the Elements Of Harmony in ancient times and used them to save the world from Discord's tyranny. Then Luna fell to evil and became Nightmare Moon, forcing Celestia to save the world from her. In modern day, Twilight Sparkle and her friends now wield the Elements (which they used to restore Luna to good), so the Princesses largely stick to their offical business. However, a bit of Celestia's former badass reappeared when confronting Discord.
She was even more badass during the Season 2 finale, when she blasted Queen Chrysalis with magic in order to protect her kingdom. Chrysalis ended up beating her anyway, but only because her power was increased from absorbing Shining Armor's love.
On some episodes The Simpsons that take place in the past, Grandpa Simpson is revealed to have been a really awesome war hero. He is shown saving his comrades from a grenade and rescuing Santa Clause from a younger Mr. Burns. He was in nearly every branch of the military and fought in both world wars. This makes his current position as the useless, senile old man even more depressing. He occasionally gets to do something cool, though, like when he and Bart tried to steal the Hellfish treasure or when he helped catch the Springfield Cat Burglar.
Special Agent William Fowler, from Transformers Prime. A retired Army Ranger (And a bit out of shape) but still fully capable of piloting a fighter jet (Still Got It) and whooping some Mook ass. He's even able to hold his own, however briefly, against Silas.
To a lesser extent, Ratchet and Soundwave. Ratchet is one of Optimus Prime's oldest allies, and even though he is still capable in combat, he generally serves as Mission Control and stays off the front lines unless his expertise is needed. Meanwhile, Soundwave was Megatron's first follower; despite being the only bot capable of holding his own against the Decepticon leader in the gladiatorial pits, he also stays away from combat preferring to be the "eyes and ears" of the Decepticons. But when push comes to shove, it appears he hasn't lost his touch.
Kim Possible's Grandmother Nana Possible can give her a run for her money.
In He-Man and the Masters of the Universe (1983) there was Granamyr, an ancient dragon who was the second-oldest being on Eternia and likely one of the most powerful. In his first appearance (the memorable episode "The Dragon's Gift") he only sent He-Man and Teela on a Secret Test of Character (and had the attitude of a Grumpy Old Man) but in his second appearance, he proved he was still a force to be reckoned with, where he kicked an evil dragon's ass but good in a rather epic aerial battle. This is not a guy you mess with. (Oh and he has a pretty Cool Helmet too.)
Edward Teach, aka "Blackbeard," retired from piracy after ditching most of his crew and settled down to live as a country gentleman in South Carolina. This didn't keep him from taking the old ship out every once in a while and indulging in some piracy when he got bored. Bribes to the governor and local judges ensured that the authorities looked the other way.
John L. Burns was a veteran of the War of 1812 and the Mexican War. At the ripe old age of 68, he was constable of Gettysburg PA. The Civil War Battle of Gettysburg began a few months shy of his 70th birthday, and Burns snagged his old flintlock and walked out to the battle lines. His ass-kicking abilities undiminished by age, he joined the Union soldiers (who were mostly a third or a quarter of his age) and showed them how it was done, even shooting a Confederate officer off his horse.
Buzz Aldrin—former NASA astronaut, decorated Air Force fighter pilot, second man to walk on the moon, MIT doctoral degree holder, and well...you get the idea—had enough of conspiracy theorist crackpot Bart Sibrel's heckling in front of his daughter and punched him right in the kisser on video when he was 72 years old.
Cinncinatus, the retired Roman general, came out of retirement and saved Rome from invaders. Then he retired back to his farm rather than submitting to the temptation to use his fame to make himself an Evil Overlord. In doing so he was held up to Roman Schoolboys for ages after as an example of faithful public service.
General, later Field Marshal and even later President, Carl Gustaf Emil Mannerheim, born 1867. He made his lifetime career in the Czarist Russian army, retiring as a fully serving General of Cavalry of the Lifeguards in 1917, having participated in both Russo-Japanese war 1904-1905 and WWI 1914-1917. After the declaration of Independence of Finland December 1917, he was pleaded to become the commander-in-chief of the White Army. After the Finnish Civil War he retired. Little did he know that his Crowning Moment of Awesome was yet to become. His happy pensioneer's days were over in 1939, when the Winter War began. Again he was called to service, as the Commander-in-Chief of the Finnish Army. He was promoted to Field Marshal in 1940, and he served as the Supreme Commander of the Finnish Armed Forces until the end of the Continuation War. After the Armstice with USSR 1944 and resignation of President Risto Ryti, he was nominated as the President of Finland. Why? Because he was the only person both Finns and Soviets could trust. He passed away in 1951.
The Tower Guards "Beefeaters" in London. Everyone is an Old Soldier who was given the position as a reward for service in the British Army.
George Washington. As if he hasn't done enough badassery in his life already, the former president was asked out of retirement by John Adams to take over the command of US Army during the Quasi-War with France.
On account of his many heroic deeds for the United States, President Washington was posthumously promoted to General of the Armies of the United States, and the same statute that enacted this promotion decreed that no American can ever hold a military rank greater than George Washington.