This character is strongly motivated by a desire to be happy and experience various kinds of pleasure. Unlike an Ethical Hedonist, however, the character isn't mature enough to sufficiently consider even his own long-term needs, much less the (short-term or long-term) needs of others. Personal instant gratification is the goal here. Sometimes Flanderized so that the pursuit of pleasure becomes the character’s only defining trait, doing whatever feels good without any thought of the consequences. "I Did It For the Lulz" might just as well be his motto.
Such a childish mentality is often justified by the character actually being a child. If the character is adult, he might be a sex maniac… lovable or otherwise.
While usually Played for Laughs, this kind of character is sometimes played as a Strawman Political against Ethical Hedonists or people with a Hedonistic Lifestyle. Unlike these real hedonists, a childishly hedonistic character is not prone to consider other people’s happiness, or even his own long-term happiness: Instant gratification is gold. If it feels good right now, do it! Why waste time on thinking? Thinking isn’t fun! Unless you are thinking about how to get what you want as quickly and effortlessly as possible, that is.
It's original to compare this general viewpoint to the original hedonists, who believed you should basically do the opposite; true happiness is the opposite of desires, which cause pain. So you shouldn't do anything you really want. You can imagine any of the characters on this page laughing ruthlessly at the idea.
Compare It Amused Me and Protagonist-Centered Morality (for this trope played sympathetically). For Happiness is another related trope.
Gauron from Full Metal Panic. He does pretty much everything For the Evulz, because he gets off on it. Even Kalinin didn't expect Gauron to be such an extreme, insane, depraved pleasure seeker. One ironically humorous moment shows Kalinin thinking to himself that, no matter what, Gauron is a smart pro that would value his life above everything else and would never do stupid things for short term pleasure. And then... a short while later, Gauron is shown getting off on his fight with Sousuke, which culminates in him attempting to commit a double suicide with Sousuke just for the pleasure of it.
The apostle Wyald from Berserk. His motto is "Enjoyment and excitement!" The fact that he says this while he is raping a farm girl who helped the Band of the Hawk who he and his Black Dog Knights have been hired to kill illustrates all we need to know about his nature.
Giriko from Soul Eater. He spends most of his free time drinking and hitting on female henchmen, he's lazy as sin, and he acts disturbingly touchy-feely with the teenage girl he's attempting to kill.
The main theme of the WantedComic Book. The hero is happy when he becomes a supervillain and begins randomly insulting and murdering people at will. Oddly enough, the villain also believes this exact same creed — he's frustrated that the current Masquerade prevents appropriately powerful supervillains from simply causing worldwide pandemonium.
Part of what makes the Purple Man so bad. He's been abusing his Mind Control powers for sex since the Comics Code Authority would allow it (and just For the Evulz for way longer than that).
This serves as Prince Naveen's Fatal Flaw in The Princess and the Frog — he's a raging pleasure seeker who doesn't want (or rather, doesn't really know how) to actually work towards anything.
Timon and Pumbaa from The Lion King. The main conflict from their part of the story is Simba's conflict over whether to continue his carefree lifestyle with them or to stand up and retake his place as king from Scar.
In the Michael Moorcock story "Phoenix in Obsidian", Earth has a dying Sun, and a large contingent of the survivors have become complete hedonists/nihilists, because they have nothing to live for otherwise.
Many Dark Others (no surprise there) but also Light Others exhibit this trait in the Night Watch series. For the former, it results in part from their philosophy's emphasis on putting self-interest about anything else, but for all Others, a combination of long-lasting youth and disengagement from human society results in boredom that they try to stave off through sensual indulgence.
Horace Slughorn from Harry Potter is implied to have shades of this.
In Atlas Shrugged, Francisco D'anconia is supposedly this, but it's all an act.
In A Song of Ice and Fire, Robert Baratheon indulged in physical pleasures to cope with losing the love of his life and being stuck with a throne he never wanted. He spends his days gorging, whoring, drinking, and hunting combining the last two gets him killed in a "hunting accident" arranged by his wife and leaves the responsibilities of ruling to his more competent advisors.
One key difference between Faith and Buffy was this. Faith lived life every second like she wanted to... and when accidents happened (like the murder of an innocent) that knocked Buffy for a loop, she merely "took care of the body" and went on as if nothing happened.
Except she was obviously feeling guilty as hell. And while she clearly enjoyed being able to do what she wanted, when she wanted, what she truly desired was a life more like Buffy's and, if she couldn't have that, make Buffy become more like her to ease the jealousy.
Early Faith is a Nietzschean, not a Hedonist. Being a Slayer (she thinks) means you are Above Good and Evil and can do whatever you want. Saving x lives means you can kill any number of people less than x, since you will still be in the plus column.
Liam was just another drunken layabout in 1750s Ireland...until he met Darla, became a vampire, and turned his tastes towards inflicting as much misery on human beings as possible.
"My lady, you'll find, that with the exception of an honest day's work, there's no challenge I'm not prepared to face."
The future version of Castiel in Supernatural episode "The End."
Gabriel (also known as the Trickster) appears to be this, tormenting others for his entertainment, creating women out of thin air, gorging himself on chocolate and other desserts. Then of course it's revealed that, although he does enjoy it, he actually means some of the lessons he claims to be trying to teach and seems a little miserable under his Trickster persona.
Then there's Balthazar (funny how all of these are angels). His reaction to the good guys derailing the Apocalypse is to grab a bunch of valuable weapons, fake his own death and start doing whatever the hell he wants on Earth ("This morning I had a menage a...what's the French for twelve?"). When Castiel catches up to him, he insists he's just following the example Cas set. "You showed me we could do anything, so I'm trying everything."
Dionysos from Greek Mythology was essentially the god of hedonism. Technically he was the god of wine, but he and his followers formed an entire religion that was basically a drinking contest. Being a Greek god, he was also a huge Jerkass to anyone who objected to his followers' debauchery — one king who persecuted Dionysos' flock (whose own mother was a follower of Dionysos) was caught spying on them and was torn limb from limb while they were in the throes of madness. Even worse, his own mother stuck his head on a stick and didn't recognize him until it was too late. Dionysos' creed was basically "Eat, drink, and be merry — or I'll kill you."
On a more highbrow note, Dionysos was the patron of Tragedy — even the name of the genre comes from him (tragedy=trag-oida=goat-song; a goat was one of Dionysos' major symbols). Whether or not this detracts from him being a hedonist depends on perspective: while your average people these days would say that tragedy's Downer Endings are mighty depressing, people who actually understand the Greeks — including the average Ancient Greek — would argue that Tragedy is actually pretty pleasurable.
Actually, Pentheus (the king in question) suffered because he wouldn't recognize Dionysos as a god; it was also about revenge. Agave, Pentheus' mother, was the sister of Dionysos' mother Semele. To shorten and simplify the story, Semele's family were mean to her when she was pregnant and wouldn't believe her when she said Zeus was the father and her son is going to be a god. Dionysos specifically wanted to establish his cult in Thebes to prove his mother was telling the truth. The rest of the family suffered grisly fates too like Actaeon (another cousin). Ultimately, the family became extinct and another royal house ruled Thebes.
The Ashwood Abbey compact of Hunter The Vigil is this. They started out as just a bunch of Rich Idiot with No Day Job types, until they made the mistake of defiling a werewolf-controlled locus with one of their orgies. Their founder decided the proper response was to arm himself with heavy artillery, start another orgy, then kill the werewolves when they came to repeat their cleansing. Ashwood Abbeyists basically hunt monsters for the fun of it, often seducing them (and/or outright raping them), torturing them and murdering them. Of course, this does bite them in the ass; their fondness for "experimentation" means they often wind up on the losing side (disembowled while trying to rape werewolves, ghouled because of their fondness of drinking vampire blood for the rush, mindcontrolled by mages, etc), and most other hunters despise them to the point many regard them as being just as bad, if not worse, than the monsters themselves.
The color Red in Magic: The Gathering is this philosophy to its Tabletop Game conclusion. It has cards that are awesomely damaging to the target...but tends to leave the caster wide open to counterattack (when the spells don't damage the caster, too). Red is passionate and powerful, but the cost of that power is that it doesn't consider the effects and often harms itself. Compare with its allied colors Black, which knows the negative side effects and chooses them anyway, and Green, which is just as primal and wild but is also devoted to the arts of healing. Contrast with opposing colors Blue, which is all about careful thought, and White, which is about order and control (of one's self and others).
The (black) vampires on the plane of Zendikar are described as hedonistic. They are also, coincidentally, said to be the most advanced race on Zendikar.
Innistrad, a gothic plane, also have vampires, though they are separated into several clans. One clan, Markov, is more hedonistic than the rest.
Combine Red and Black and you get people like the Rakdos Guild in Ravnica. The passion of Red and the selfishness of Black creates hedonists that not only don't care about the consequences to themselves but also don't care about who else they might hurt with their debauchery.
Slaanesh from Warhammer and Warhammer 40000. He- she? it?- is literally the manifestation of all the Squick in the universe, while his followers are to a psychopath in it either For the Evulz or because Evil Feels Good. Lest we find the idea of a cult of hedonists even somewhat non-threatening, remember that this is 40K and their idea of a good time probably starts with "violate your intestines through your belly button" and just goes in whatever random direction they can find from there.
In 40K, Slaanesh was literally Squicked into existence by centuries of Eldar engaging in ever-more depraved acts of debauchery, reshaping the Warp until he/she/it manifested in a humongous Warp storm. The Eldar now refer to Slaanesh as "She Who Thirsts", and take a great many precautions to prevent her/him/it from eating their souls on death.
While the Craftworld Eldar and the Exodites have renounced their hedonistic ways and follow the path of rigid self-control to keep themselves free of Slaanesh's influence, the Dark Eldar are just as bad as the pre-Fall Eldar, if not worse after they figured that not only is Cold-Blooded Torture fun, but it also allows them to stave off Slaanesh draining their souls.
In the Dungeons & Dragons setting Planescape, the Sensates are a faction dedicated to experiencing every sensation and act that they can — good as well as bad. Many members take this as an excuse to become hedonists; they are looked down on for indulging one sensation—pleasure—to the exclusion of all others, and to blinding themselves to new experiences. These members are commonly sent to a hold the Sensates have in Arborea, where they get to do nothing but blindly indulge their hedonist ways, over and over again for the rest of their lives without ever experiencing anything new (and before you ask, the door is open. Anyone sent there can leave any time they want. So far, nobody has).
Fiyero in the musical Wicked: "Nothing matters but knowing nothing matters... It's just life, so keep dancing through!"
Well, at least until he goes through some massive Character Development and some of his frivolous comments and beliefs become painfully ironic.
Val in Babes in Arms declares himself to be this (although whether he remains so is unclear, since his ideologies shift constantly).
In Antony And Cleopatra, this trait is shared by the Egyptians. Antony has also adopted the tendency due to being in Egypt for so long.
Count Henri de Bouvray in Victor Herbert's Mlle. Modiste: "There's no worldly pleasure myself I deny,/There's no one to ask me the wherefore or why..."
Morinth of Mass Effect 2 is a killer afflicted with a condition that makes her kill those she has sex with, which has an addictive effect upon her. She's been spending centuries getting her kicks with either slaughter, music or drugs as well as evading her mother Samara.
Isabela from Dragon Age II seems to live for three things: the thrill of adventure, alcohol, and sexual gratification (from men and women both).
Sebastian admits he used to be a hedonist before his family sent him to the Chantry. When Isabela hears this, she complains that she should have met him back then instead of now.
After only getting two or so scenes in Kingdom Hearts II, Demyx was somewhat fleshed out as this is Kingdom Hearts 358 Days Over 2. He's more interested in writing songs than following orders, and isn't above bribing Roxas to finish his missions for him.
Suika Ibuki from Touhou, who has never been seen sober for centuries. Most other characters in Touhou also have various vices that they indulge in. It helps that the majority of them aren't human.
In Asura's Wrath, Augus has Greed as his Mantra affinity, and it shows. He lives for pleasure above all else: sleeping with beautiful maidens, eating good food, drinking fine wines. Most of all, he enjoys a good fight.
Augus: "Relax my son. Enjoy every moment. You fight, then you eat good food. You fight, then you drink fine wine. You fight, then you sleep with beautiful women. Hell, fight with Beautiful women! That's what it truly means to live."
Diablo III has Azmodam. Justified because he is the lord of sin.
Mother 3's main villain and returning antagonist, Porky has traveled through time and space to experience every little bit of joy he can in his extremely long life. After perhaps thousands of years, he has decided to end all existence, just because it's the only thing he has yet to do. Eventually, he's sealed in a capsule that cannot be broken into or out of, forever, and he enjoys it.
In Assassins Creed III, Thomas Hickey is one of the villains, but unlike the other Templars that Connor assassinates, he's not in it for their principles of Order; he just goes along with them because they pay well. All he wants out of life is girls and booze, and his Motive Rant to Connor is all about how he, unlike the Assassin, can have what he wants. That is, until Connor kills him.
In The Gungan Council, Deagan Hunt and XoChitl Salvaje, as Zeltrons, and Kirk search for the thrills and pleasures in life for their own reasons.
In an episode of The Simpsons a self-help guru gets the entire town going on this motto — specifically, acting like Bart. The whole thing falls apart at the festival celebrating this newfound freedom, the main catalyst being when a handyman decides he didn't "feel like" greasing the Ferris wheel so it wouldn't fall off its hinges and go on a rampage.
Hedonism-bot of Futurama. How hedonistic is he? He's so hedonistic, he has his solid gold body smothered in chocolate.
The DVD commentary for Futurama stated that he was not simply a hedonistic robot but he was hedonism itself, which is why he is not called "Hedonist-bot". It wouldn't have done him justice.
How wonderfully decadent!
And he apologizes for nothing!
Your tax dollars at work!
Beezy on Jimmy Two-Shoes lives his life basically eating, sleeping, hanging out with Jimmy and dating Saffi. He seems to put his happiness first beyond anything. He's still one of the few decent people on the show.
General Iroh from Avatar The Last Airbender pretended to be very much the hedonist, much to the chagrin of his naive nephew who refused to see that the evil empire didn't deserve their loyalty. For Iroh, life's little pleasures are more important than doing his duty... but only when his duty is actually evil, destructive or plain unworthy. Whenever he has a worthy cause to fight for, he's dedicated and self-sacrificing if needed.
The Larry 3000 seems to split being The Spock and The Hedonist about 50/50. He gives a good show of being uptight and prissy, and the casual viewer might mistake him for being the Only Sane Man to Tuddrussel's Boisterous Bruiser, but truthfully the a nice chunk of the mission hang-ups happen as a result of him getting distracted and siding with whomever is messing up history if they promise more fun than fixing it would.
What little we see of John Corben's character in Superman The Animated Series shows that he's quite the hedonist. He surrounds himself with luxuries in his prison cell while enjoying gourmet food, all of it courtesy of Lex Luthor. When he gets out of prison and is transformed into Metallo, one of the first things he does is force a kiss on Lois Lane, remarking that he had been thinking about her during his entire stint. His initial joy at being transferred into a superstrong robot body swiftly turns into horror when he discovers that he couldn't feel the kiss. His new form has no sense of taste, touch, or smell.