Riku in Ansem Retort is the target of countless acts of violence that should have killed him by now. He's been cut in half God knows how many times, burnt, blown up, electrocuted, stabbed, violated, tortured, and even had his heart removed. While he found a girlfriend in season 5, for the most part, even the comparatively friendly characters in the comic go out of their way to hate Riku.
Sometimes Marluxia fills in, as does Sora, who forgets it quickly.
Rick from Basic Instructions almost borders on Cosmic Plaything, the way the universe and everyone has it in to make sure he's never happy. Even his best friend insults him quite often.
In Captain SNES: The Game Masta, Alex gets this treatment. Enough so that he recognizes as such and wonders if the whole of Videoland isn't out to get him somehow.
Alex: I've noticed something recently. I don't know precisely how to put it. Whenever I'm about to accomplish something, or to defeat something, or to accomplish something great, something ends up messing it up. Like when I went to shoot Kain, or when I went to open the last treasure chest up.... It's like.... It's like someone or something is conspiring against me... Making things harder for me, on purpose. It's like Videoland is trying to...well, mock me.
Bob: Are you sure you're not just being paranoid?
Manual: You've got the book (again!) What wondrous powers have you failed to unlock you stupid, stupid boy?
Cucumber in Cucumber Quest will never have his way. It's also mentioned that Carrot was one of these when he was in the BLT trio.
Jyrras Gianna from Dan and Mab's Furry Adventures never seems to get a break. He's frequently harassed by his family, choked by girls, teased by Abel, written into an embarrassing novel, and finally, cursed by The Fair Folkshortly after having a nervous breakdown when discovering his feelings for his best friend and, as a result of the Fae meddling, has been declared "Bachelor of the Year" by a major woman's magazine, which sounds great until you remember he hates people calling him cute, is painfully shy and, oh, that said best friend is a guy. Good Lord!
Frieza, of all people, becomes this. Put simply, no one in the tournament is on his level, since the story is post-series and everyone else has either beaten him or beaten the guys who beat him and trained up. The only exceptions are the people who are too weak to fight him, who forfeit instantly. In more than eight hundred strips, he still hasn't won a fight. He gets humiliated and killed in Universes 3 and 7 (and it's obvious the same thing will happen in others, like U13), it's been hinted that even in the one where he won he had some troubles, and it already seems that he will be defeated by U18 Goku without having landed a single hit on an opponent. Even Nappa manages to mock him.
To a much lesser extent, Dabura. He spends many chapters weakly asking to be healed before actually being healed.
The Dreamer: Poor Nathan. He gets beat up when trying to apologize to Alan, has to escort Bea back to Boston, his Colonel doesn't think he's competent enough, and he's never even been in a single battle.
Syphile from Drowtales. Also crosses into Woobie territory for some readers, since at least at the beginning comparatively little of it was her fault, while some of her later failures (and eventually her death) were more due to her own malevolence or stupidity, especially her actions towards her own adopted sister.
Luke from FreakAngels. He was recently healed after a bullet through the head, and had a penis drawn over the spot of new, whole flesh on his forehead where the bullet entered, chemically castrated by the doctor without his knowledge, and know people are considering wiping his memory. Granted, he is a psychic rapist...
Moloch Von Zinzer from Girl Genius. He does start by bringing it on himself, what with helping his brother steal Agatha's locket but given his brother dies, getting taken prisoner by Baron Wulfenbach under the misaprehension he's a Spark, getting sent to Castle Heterodyne when it's discovered he's not, winding up as Agatha's reluctant minion since helping her is the only way he can possibly regain his freedom, having the Castle near-miss him with death traps for shits and giggles, and having two and possible three girls, all of whom are potentially dangerous and at least two of whom know how to kill while the third is definitely a potential Axe Crazy where her rivals are concerned, all as romantic interests seems like somewhat disproportionate retribution by the universe.
Greg from Greg, has had it so bad, that he considers stepping on dog poop a considerable improvement over the events that occur in his life.
The character Head-leg (a head on a leg, go figure) from Irritability was literally made by Evil Genius Exoth to be tortured and die in horrifying ways over and over again. Exoth just doesn't like poor Head-leg.
Nothing ever goes right for Miles. And if something actually does, it will likely end up backfiring horribly for him, and amusingly for the readers.
Matchu has Matchu and Amber, Star-Crossed Lovers who can't get near each other without something bad happening. The one time Amber actually acknowledges Matchu's presence, a UFO lands on top of him mid-sentence.
In Ménage à 3, Gary's misfortunes sometimes seem to be the comic's main source of humor, although it's arguable that he brings a lot of his troubles on himself, and this trope is eventually averted by stages. In fact, for all his misfortunes, Gary leads an increasingly interesting life from the comic's first strip onwards; his big problem may simply be an inability to capitalise on his moments of good luck. For example, his favourite (ex-)porn star Amber becomes interested in him sexually, but then manages to drive him off thanks to his inability to handle her confusion about his exact sexual orientation. Likewise, he eventually has two attractive women competing for his attentions — but neither pays any attention to any ideas he may have about the matter.
The June 4 2013 strip, number 750 (NSFW), perhaps marks the point beyond which nobody can classify Gary simply as the comic's butt monkey. Having vanished, a little worryingly, from his apartment, Gary turns up in Paris, in the company of a naked fashion model, looking understandably fairly cheerful. Meanwhile, most of the rest of the cast are suffering break-ups and traumas. Which said, he does still suffer occasional uncomfortable incidents, even on that trip (see this strip from Spin-Off comic Sandra on the Rocks) — but everybody's life has its ups and downs.
morphE features Tyler Dawn, a Forgetful Jones who forgets important information and sucks up close to the kidnapper who is keeping the group imprisoned. He is fiercely competitive with the other captives but lacks any skill to follow through with his passion. For these reasons and more he is made to look a loser and failure. "God damn it, Tyler" is being said more and more each chapter.
Eerie Cuties: Ace has the misfortune of being a nice guy, who just can't catch a break. The few times things seem they're about to go his way are usually subverted, or short-lived. His longest (and only) bout of good fortune was when he successfully hooked up with Brooke, at the end of vol.1. Which came to an end between Melissa and Tia each interfering in their relationship. And just when you think he'd had enough misery heaped upon him, in chapter 15, he gets stuck with Blair in his body.
Myrith McRain from Mortifer. It starts with Joey capturing him, chaining him to a desk near the breakroom, and forcing him to do hacking work to find black market kingpins. But the crowning moment of this has to be when Alyce, who is revealed to have known him from childhood, finds out he's there... And, well, justlook.
In MS Paint Masterpieces, we have Polka Reset Man who started out half built and, an hour later, half of the rest destroyed and it all went down hill from there.
Nodwick is one of the many butt monkeys who adopt the Deadpan Snarker path to make up for it. Even when he isn't shown on screen suffering from fates ranging from being eaten by an ogre to being actively disintegrated by evil adventurers, his employers will put him through some very weird stuff for a quick laugh. And then there's the henchapult....
Ivan the apprentice of a sadistic tyrant sorceress in Oglaf has had more spotlight than any other character, and all the more witness to his suffering. Whether or not he's actually been killed, death would be a kinder fate than he'll probably get.
Garth from One Phone Call is in the process of telling one of the most improbable stories ever. Over the course of one week, his apartment burned down, he lost his job, he was suspected of domestic terrorism, he had a heart attack, he accidentally aided some master criminals with a casino robbery, and his car exploded in the ensuing police chase. And he's just getting started.
To a certain extent, Vaarsuvius from The Order of the Stick, who in the recent arc keeps getting screwed over by the plot in painful and imaginative ways.
To an extent, the entire Order of the Stick. To quote V, "It is troubling that we can now recognize our failures by immediate auditory familiarity."
Lenny from Our Little Adventure. He's the one who has to lug the group's treasure swag around, and Angelika and Rocky are often pretty mean to him. Some of their treatment towards Lenny might be due to his passive nature.
Johnny Turringer, a bit player from Webcomic/Precocious. He's made it in-panel once, before his most notable trait is developed: somehow, Max (the only nice kid in the main cast!) ends up causing him some sort of injury. Every time Johnny's come by after was preceded by some sort of crunch sound, as if a bone was being broken ...
Zoe from Sluggy Freelance is this in a mountain of spades. One has to wonder, being that several characters in the series are based on people the author knows, if Zoe is based off some one he hates.
On Zoe's first appearance, very first panel in fact, she got locked out of her car with the engine running and then (two panels later) promptly ignored by the people she was asking for help in favor a chick with a pair of three-of-the-letter-that-comes-after-Cs. Shortly after she gets her arm twisted by the same guys because of an armada of other multiply-barely-passing-grade-letter endowed women. A few minutes later she meets Bun-Bun... 'nuffsaid. Then, minutes later as she is sitting, minding her own business, recovering from her previous wounds, she gets hit in the head by a frisbee thrown by one of the previously mentioned improperly-counter-weighted women... then immediately trampled by torg, riff, and the entire Keeping-the-Plastic-Surgeons-in-Business Association... And then immediately trampled again... and then, just to ice the cake with a layer of frozen Zoe blood, she get's meated by Bun-Bun again... as her INTRODUCTION!
But that's not even the worst of it. Since then she has been cursed, had said curse abused for laughs, chased by a psycho unkillable mind controlled gymnastic super assassin that wants to kill her over a love triangle Zoe has no active part in, had her best friend be possessed by a demon, had her first romantic interest in the comic gorily killed by devil-cats right in front of her, oh yeah... had to run for her life from said devil-cats, teleported back in time and forced to act out a prophecy to kill aforementioned demon, is now hunted by demons world wide, kidnapped to be experimented on, given the mother of all meddling mothers, nearly loses her family to keep her job, ostracized by her friends also because of job, other-dimension widowed, other-dimension killed by a different set of demons, kidnapped by Russian mobsters (who thought she was a camel), and (because the author apparently wasn't satisfied with everything up to that point) burned to death in roughly a billion different dimensions at the same time. I'm sure I missed a few... dozen.
At which point, when it was revealed that she was actually alive but worse than brain dead... it was somehow still an improvement.
Efengi from The Snail Factory is constantly put through various types of torment and nearly fatal disfigurement. He may also be considered a chew toy, depending on how you look at it.
Davan of Something Positive. Within the last three years, his long-time girlfriend left him to pursue her dream job, his mother died, his father was diagnosed with Alzheimer's, he's had a paternity scare (which the author admitted he almost made Davan the father just to spite some of his critics), and his acting career is a string of roles as rapists and psychos. All this doesn't even include the casual cruelties heaped upon him by his (so-called) friends.
Some might argue Mike is a bigger Butt Monkey, but it's clear that most of the stuff that happens to him is both deserved and self-inflicted.
And let us not forget Kharisma, who was burned and disfigured and was sent to prison for life for a murder that, ironically, she didn't even commit. (Why is that ironic? Because she was actively trying to kill the person whose death sent her to jail.) Then she escaped, went on the run, and found herself working as an enforcer for a meth dealer.
Sore Thumbs: Fairbanks, the Strawman Republican, who at this point is even starting to actually resemble a monkey. (It's all about the ears and facial expressions!)
Before the comic even began, she discovered that her sister Amber was a porn star by being exposed to one of her films at a party — when she was 14.
During her first evening in the comic, she accidentally gives two other characters a Panty Shot, stumbles on a collection of Amber's porn work, finds two of Amber's sex toys just lying around, and then ends up hiding in a wardrobe, watching and then listening while two gay men have sex (which she doesn't enjoy).
The next day she has it pointed out to her that her favourite tutor at university was an exploitative pervert, and her long-standing wardrobe choice is therefore deeply embarrassing.
The day after that, there's the trip to the swimming pool where she nearly drowns and then experiences what feels to her like a minor Humiliation Conga. It just goes on from there...
Subverted in Tales of the Questor where the lead character, Quentyn, is the apparent Butt Monkey of the story. He is a runt, bullied and put down by many of his peers, the governing counsel of his town largely doesn't take him seriously, and he is unable to use the Lux power around him like almost everyone else. However, when he finally makes the big sacrifice that gets him hailed as a hero in his hometown, the chief bully, Rahan, drunkenly complains about how Quentyn actually has an unfair advantage. Rahan wails that since Quentyn is seems to be such a Butt Monkey to everyone, they always feel sorry for him and thus he has gotten away with a variety of antics that would have had anyone else run out of town. Quentyn comes close to believing that, but his friend Kestrel reminds him forcefully that he deserved that sympathy and he never abused it.
Igor in Vinigortonio. If something bad's gonna happen, it's bound to happen to him, and it becomes even worse when he finds out the leader of an evil organization needs to destroy his building in order to conquer the world.
Almost the entire cast of the webcomic 8-Bit Theater takes turns being the Butt Monkey. Black Mage takes center stage (Brian has even flat-out said "everything that happens, happens to hurt Black Mage"), but Fighter is being stabbed by him almost constantly. Red Mage gets his fair share of pain. White Mage is emotionally tortured by the utter lack of interest the chosen warriors have in their quest and the frequency with which they kill innocents or each other. Garland, the first boss, started as this before becoming just incompetent. The recurring Onion Kid character only even exists to have his new foster families casually slaughtered. Thief has to deal with Berserker attacking him at sight and being torched by Bahamut, and Black Belt got near-slaughtered by several encounters including Black Mage, until he eventually died. In a mild subversion, Black Mage actually deserves Butt Monkey status.
Also, recently, Sarda has revealed that he too is a Butt Monkey in a roundabout way — he's the Onion Kid, all growed up and looking to exact vengeance upon the ruffians that repeatedly ruined his life. Not only that, he's his own Butt Monkey, because as Red Mage points out, all the bad things that happened to the Onion Kid, almost without exception, happened because Sarda sent the Light Warriors on their quest in the first place.