These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Some "Fubblegum" shippers sorrowfully tied up their ships and left them at the dock after "Too Young" reveals that Princess Bubblegum won't date Finn because of the age difference, and she told the boy to "move on."
Some "Finnceline" shippers did this after Marceline's ship sinking with Finn in "Go With Me."
Some Finnceline and Fubblegum shippers left their ships to join the ranks of the Princess Bubblegum and Marceline ship.
After the premiere of "Incendium," various shippers (but "Fubblegum" in particular) are leaving their old ships in favor of Finn/Flame Princess
In-Universe, in the episode "All The Little People" Finn ships and abandons several pairings.
Most "Lemonzest" shippers stopped shipping the Lemongrabs after "Another Five More Short Graybles" reveals that they are actually brothers.
Not to mention one eating the other.
What shippers that were left jumped ship after "Too Old".
"You Made Me!" has spawned a ton of these. "If you can't love yourself, you can't love somebody else"? "Everyone has a soul mate"? "A negative times a negative equals a positive"? "Friendship makes everything better"? "You are your own worst enemy"? Take your pick- they all work out nicely.
One moral that could be construed from "Too Young" is "Inexperienced, immature people should not be given positions of leadership."
Ironically, the exact opposite is lampshaded by Finn in "Too Old," stating that "older people aren't as fun."
Alas, Poor Scrappy: If you viewed Lemongrab 2 as an example of this, then this trope would definitely hit you when Lemongrab devours him.
A loser and jerkass who always tries to force princesses marry him, a tragic Woobie who just needs a hug and a reason to be happy, or is his mind just too muddled by the crown for him to fully comprehend that what he's doing to other people is wrong?
Ice King: I don't know... I'm complicated.
Princess Bubblegum is quite probably the most divisive character on the show.
Alternatively, Bubblegum may simply be a very stressed out young adult with a lot of responsibility on her head (having to run the Candy Kingdom while also trying to keep everyone safe and calm from all the weird calamities that seem to occur on a rather frequent basis), and is just trying to let down Finn (who is 5 years younger than her) with as much tact as possible.
Was she legitimately jealous of Finn and Flame Princess, or as indicated simply more concerned for everyone's safety due to her knowledge of Flame Princess' volatility and danger? Or both?
Was creating Lemongrab and her subsequent mishandling of the situation morally repugnant or just poorly handled? Hard to say, though a significant portion of the Headscratcher page is devoted to this.
Was her creating a clone of herself for Braco a genuine gesture of care and a way for her to make him happy, or was she just being selfish and finding an easy way to get rid of him?
In "Too Old," she walks away when she sees the mentally challenged lemon kids getting abused by their dad. She only chooses to save the smart, "gifted" one because she wanted to put him into a school for talented children. She ignores the other ones even though they were abused, too. She also went back on her promise of "keeping an eye on the Lemongrabs." Because of her negligence, she allowed Lemongrab to eat his brother and abuse all of his children.
In "James," was Bubblegum basically sacrificing James to save Finn, Jake, and herself as justified as she claims or was she going over the line despite her good intentions? Even Finn and Jake are unsure of the answer in-universe. This episode essentially called into sudden question just how far Princess Bubblegum is willing to go for the greater good.
Selfish Jerkass tyrant in need of a good kick in the butt, or a genuinely psychologically unstable person in dire need of help and kindness, or both? After "You Made Me!," it seems that last one is the most likely.
Safe to say he's quite a bit smarter than he would let on, but to what extent? Word of God confirmed that Lemongrab was the one who built the Sound Sword. It's not far of a stretch to imagine Lemongrab could even be a Genius Ditz, as it has been demonstrated in Real Life that autistic people can be incredibly skilled in some specialized areas.
Was Lemongrab 2 an insensitive Ungrateful Bastard for not caring about Lemonjon's death? Or was he simply stunned and unable to completely process what had just happened? His increase in empathy toward his children afterward (as opposed to his brother) hints at the latter.
In "Too Old" (his presumably last appearance), did Lemongrab abuse his children and possibly kill his clone because of his extreme mental problems? Or was he lashing out because of his grief over Lemonjon's death? Considering the thoughts he had in his brain after Lemonjon's death ("RAGE," "SUFFER," "call me crazy, but it's time we die") supports this. Some even see him as a hopeless Woobie, Destroyer of Worlds that probably has a sad fate at some future episode.
Magic Man: A complete jerkassTroll, a massive hypocrite, a ruthless sadistic bastard, or an insane man mourning the loss of his girlfriend?
This actually gets brought up in "Wizard City", with Princess Bubblegum pointing out to Jake that his powers are probably a genetic mutation not magic like he thinks.
Before her first physical appearance in the series, Betty got quite a bit of this, due to her having a pretty big role in the Ice King's backstory. The interpretation boiled down to whether she really was as nice as Simon made her out to be, since she left Simon after he went on some kind of nutty rant under the crown's influence. That interpretation was completely Jossed in her own title episode when it was revealed that Betty never truly left Simon, simply jumped into the portal to the future to be with him, and showed her dedication to Simon by promising to find a way to free him from the Ice Crown.
To some, Braco was a massive woobie who was absolutely deserving of PB's love, and was unfairly rejected. To others, he's an entitledstalker, and was way too willing to settle down with the PB-Bot (casting doubt on whether he really cared about her as a person in the first place).
Finn: Actually, I've never even met any other humans. If I think about it too much, I get all soul-searchy, and weeeird.
He may technically be the last human, but there are plenty of humanoids, and just about every creature is sentient so he has no lack of companionship.
This seems to be Finn's mentality with everything (not surprising since he lives in a very weird world, and it's inevitable that he'll have to block things from his mind). For example, in the "The Creeps," he happily stores away his memory of the real ghost in his "vault." In "No One Can Hear You," when Jake asks how Finn's legs are doing, he replies "Still broken," with a smile.
Jake doesn't seem too put off by the fact that his children age so rapidly, they're technically older than he is. Averted in "Puhoy".
Finn and Jake don't seem to have been affected by Billy's death all that much.
In-universe (and played for attempted laughs,) Ice King didn't care at all that Princess Monster Wife died.
In "Puhoy," Finn has a dream (maybe) about being trapped in a land of pillows. He shows surprisingly little angst about never seeing his loved ones again (granted, by the time we see him he's already been there for years). That said, the fact that he's spent literally all of his adult life in the pillow world and then some searching for a way to return to Jake and his home world suggests that he's been immensely affected by the loss. (He gains some meaningful character development through the episode coming to terms with and accepting that the pillow world is his new home, and it takes decades.)
Lemonhope is a cheerful, chipper little boy despite a life of being abused by a violent, unstable father, witnessing the abuse of all of his siblings, and eventually witnessing his father eating his other father. Despite all of that, he remains, seemingly, optimistic and hopeful, hence his name.
Applicability: "All the Little People" has been interpreted as being one big, long Take That to obsessive shippers  and/or symbolic of Finn’s "pubescent sexual awakening," and/or symbolic of the crew's creative process. 
Ass Pull: Cinnamon Bun's sudden boost in intelligence by means of baking was debated to be this by the fans mainly because he was wearing the Flame Shield, which was supposed to protect the wearer from extreme heat.
Award Snub: Some fans felt that the Adventure Time episode "Too Young" was robbed of the 2012 Emmy by Regular Show's "Eggscelent". Because the Adventure Time fandom largely overlaps with the Regular Show fandom, many fans thought that AT winning the Emmy would have robbed Regular Show!
The Abraham Lincoln scene in the pilot. When he shows up again in the series proper, it's just as jarring to people who haven't watched the pilot.
The ending to "The Other Tarts."
In "What Have You Done" when PB flips a table and starts shouting in German before fainting from exhaustion. The table flipping is understandable, but it's never mentioned why she is exclaiming in German.
Jake's Dream Sequence when he falls asleep during Princess Bubblegum's lecture:
Jake: Where am I?
(the camera pans over to show a tiny giraffe, a tiny snowman and a tiny version of Tree Trunks)
Tiny Snowman: Jake, you're president now!
Jake: Oh my gosh!
(Jake proceeds to sway back and forth while the tiny snowman, giraffe and Tree Trunks all clap.)
The scene in "Beyond This Earthly Realm" when the Ice King breaks the fourth wall and proceeds to make an elaborate speech to the audience.
Finn's premonition dream in "The Lich" is incredibly random, aside from the key moment where the Lich kills Billy.
The scene in "A Glitch Is a Glitch" where Jake's arm and PB's hand make out. Yeah...
Bizarro Episode: "BMO Noire" makes no sense, even by this show's standards.
Also the "Fionna and Cake" episodes, which have gender-flipped versions of everyone in the cast.
The best contender so far has to be "A Glitch Is a Glitch" for its CGI Art Shift and exceptionally weird presentation.
"Puhoy" is an episode spent almost entirely inside a pillow world that may or may not have been a dream. Similarly, "Rainy Day Daydream" is an episode about Jake inexplicably gaining Reality Warper powers via his imagination. Basically, expect weird stuff that doesn't normally occur to happen when there's a knife storm (which is in itself weird).
"Too Old." Those who like it are fond of it for its darkness, drama, and suspense. Those who hate it absolutely despise it for the the Unfortunate Implications of Lemongrab's actions physically and verbally abusing of his kids and clone, and eventually committing presumed murder and the fact that only Lemonhope was rescued at the end (see Unfortunate Implications below).
Complete Monster: The Lich is an Evil Sorcerer who desires nothing less than the extinction of all life. While most of the series' antagonists have sympathetic moments or funny quirks that add levity to their crimes, the Lich is the only villain to always be played absolutely seriously. His attempts at wiping out all life has included possessing Princess Bubblegum, going One-Winged Angel, and rampaging through the Candy Kingdom; killing and possessing the body of Billy as part of a complex gambit to get a Reality Warper named Prismo to grant his wish for the extinction of all life across The Multiverse; murdering dream Prismo as well as Prismo's physical body, the latter solely For the Evulz, then breaking the universe's worst criminals out of their cosmic jail, all in order to create an unstoppable army for himself to lead in wiping out all life, one planet at a time. The Lich is also heavily implied to have been involved with the destruction of mankind and one of the reasons why the show takes place in a world After the End.
Continuity Lock-Out: Susan Strong refers to her people as "Hyoo-man" in her second episode, which sounds exactly like "Human." The term "Hyoo-man" was clarified to mean Fish People only in supplementary materials. Anyone who hadn't seen them would be confused, since the difference between Human and Hyoo-man happened to be a plot point that was brought up and discussed.
Counterpart Comparison: Since "Holly Jolly Secrets," viewers have been comparing Ice King to Mr. Freeze, though the circumstances in which they were separated with their lovers are fairly different.
Crazy Awesome: Finn and Jake's dad, Joshua. Amongst other things he's fought all kinds of monsters and demons, built entire dungeons just to make sure his sons are badasses themselves, knows spells that make enemies explode into fire and banishes them to the Nightosphere, and forged and wielded a sword made out of demon blood. No wonder Finn and Jake turned out the way they did.
That Schrödinger's Cat thing in the dungeon episode - mostly because of his compelling voice (provided by Clancy Brown,) and him saying, very casually, that he would "unzip Finn's skin and wear it like a little coat."
Lemongrab get a dose of this in "You Made Me!". He reveals that his sword shoots sound blasts, and it's implied that he's an inventor of sorts. He apparently made a room whose sole purpose is to electrocute people through the floor. Okaaaaaay...
The Lich. He's the Big Bad of the show, and is so scary that he's somehow amazing.
Goliad! A cute candy sphinx with a baby face and the voice of a little girl, who mind-controls people using her psychic powers.
MAGIC MAAAN!!! He's funny and scary, at the same time. On one occasion, he whistles, which causes a bird to flutter down and land on his finger. With a wave of his free hand, the bird gets turned inside out, and flops away.
Jake, arguably. He's pretty lazy sometimes and he has stolen on more than one occasion, and even outrightly discouraged some altruistic actions a few times.
Princess Bubblegum can come across this way when one remembers that her scientific mistakes, especially the ones which involve her playing God, are what cause many of the problems in the show. The fact that she never appears to learn her lesson doesn't exactly help.
Finn in "Too Old." He legitimately doesn't care about helping the lemon people and Lemonhope and instead spends the whole episode trying to flirt with and impress Princess Bubblegum (which is inappropriate to begin with not only because he is using her as a rebound girl after his break-up with Flame Princess, but also because they are on a diplomatic mission). Why isn't Jake there? Because Finn told him that Princess Bubblegum doesn't like him anymore.
Designated Villain: This trope was a major plot point in "Donny." Donny's meanness counters the Why-Wolves. He's shown to be, deep down, a VERY nice dude.
Flame Princess got initially just for being a Third-Option Love Interest to Bubblegum and Marceline, but later got a more subdued version of the trope because she couldn't even touch Finn without hurting him. It eventually all but evaporated after she and Finn permanently broke up.
When this trope is applied to her, Princess Bubblegum becomes a sociopathic monster who only fake cares about others as long as she can use them.
Bubblegum also gets hit by what can only be called a reversed version of the trope, as people will ship her with anyone, especially Finn and Marceline, despite her showing clear and firm signs of not wanting to be in a relationship.
The Ice King, now that we know his past. He's easily much more sympathetic, and the show itself has toned down his evilness and upped his doddering insanity since past the first season, but some people go so far as to say he isn't a villain and his kidnappings are harmless and alright.
Although, considering his Ax-Crazy behavior and his extreme change in physical appearance in "Too Old," this is very divisible now.
Ash, too, for the same reason Marceline ignored his bad traits: He's a punk rocker bad boy.
Marceline became equally as popular as the lead characters despite only appearing a couple of times in the first season.
The Lich got a lot of attention from fans before he even appeared in the show, mostly for a really, really cool design.
The ENTIRE Gender Flipped world rivaled the normal one in popularity even before "Fionna and Cake" was made. Special props, however, go to Marshall Lee, who is probably the most popular one of all, despite his only appearance in that episode being a silentcameo. The episode dedicated to him made him even MORE popular, especially because he's genuinely much more of a mischievous, traditional trickster than Marceline is.
ANY character that is female, young, and has a fit humanoid body, including Celina, Doctor Princess, Jungle Princess, the Nymphs, the Bikini Girls and others, generally for fanart, shipping and Rule 34.
Jake's dad, Joshua, seems to be rather popular.
Before "Jake the Dad" aired, of Jake and Lady Rainicorn's kids, Jake Jr. seemed to be getting the most attention and concern, because the kid lacks a face.
Betty is depicted in a lot of fanart, despite being mentioned in only a couple of sentences in the whole show.
Her popularity increased after her arrival in Ooo and she turned out to be a Badass.
James from " James" seems to have a very loving fan base as well, it helps that, coupled with his funny mannerisms that he's voiced by Brak.
Epileptic Trees: It's extremely likely that Phlannel Boxingday is actually Princess Bubblegum in disguise: both are pink; have an identical face apart from the mustache; have the same initials and same number of letters and syllables in their first and last name, Boxingday's last lines include Gratuitous German ("In deinem Kopf."), references to being unable to interfere in Castle Lemongrab's policy due to treaties and Techno Babble. The only other possible explanation is that Boxingday is a "sibling" that came from the same pile of goo where she came from.
Possibly the ending of "Tree Trunks"; she did look happy... and then subverted when we find out what really happened in "Crystals Have Power."
The ending of "Holly Jolly Secrets" definitely. It shows the start of a new, Christmas-like tradition for Finn and friends (also Phil), but anything involving the Ice King will never be the same again after what we saw in the final minutes of that episode.
Ice King's female counterpart, Ice Queen. Presumably, this is to contrast with Ice King's... undesirable appearance. Nonetheless, Natasha Allegri said that she made Ice Queen attractive because she thinks attractive villains are scarier. Justified considering she's the Ice King's Author Avatar.
Many fangirls see Marshall Lee in this light. It's debatable whether he's genuinely evil or just mischievous, but he's MUCH more threatening than Marceline... and he's also more explicitly enticing and flirty.
Marceline, as well. While their wickedness is a debatable in recent episodes, still counts. Now, she is more of an Anti-Hero.
"Tree Trunks" suggests that you shouldn't encourage people to "follow their dream" if they simply don't have the necessary characteristics for it, as it will probably lead to disappointment or something even worse.
The moral of "His Hero" is that sometimes violence can be more helpful than nonviolence. Considering the show's nature (see Broken Aesop), this might be a joke, but it's not entirely wrong.
The moral of "Freak City" seems to be that some people are just jerks and that sometimes you have to deal with them. Again, not entirely wrong.
The moral of "All Your Fault" is that having more children than you can feed will create hardship for your family and community.
The moral of "Conquest of Cuteness" is that using your cute looks and charm to manipulate others is better than using violence.
The apparent moral of "Too Old" is that an abuser's violent behavior will escalate if they are not held accountable, and that such abuse can even culminate in murder.
Also, some people are too far gone to be redeemed, and progress made will sometimes be reversed.
Fan Dumb: Like any fandom, there's a dark (and thankfully minor) side to the fandom that can have stupid and disturbing thoughts about how a situation should be handled.
Fan Nickname: Lemongrab 2, Lemongrab's clone, is commonly referred to as "Buttgrab" by Adventure Time fans, because A) he apparently has an enormous bottom, B) he was butt naked in his first appearance, and C) the fans wanted him to have a name to differentiate him from his predecessor.
Faux Symbolism: Fans have been relating that scissors incident in "The Lich" to Finn and PB's general relationship as of late. PB accidentally cutting Finn supposedly represents PB hurting Finn without intending to, something she's been doing frequently. Finn trying to gain PB's gem and her telling him to back off supposedly represents her rejecting Finn's love, and in the process, unintentionally hurting him.
The catcher's mitts from "You Made Me" inspired a load of theories on the nature of their existence and their symbolism. Thomas Herpich, the writer of the episode, refused to tell the fans what they meant, because A) he wanted it to be mysterious, and B) he found the fan theories to be fascinating. However, the lead character designer, Andy Ristaino, later revealed the symbolism of the mitts on his Formspring. As it turns out, the real symbolism was so complicated and strangely obvious that no one would have guessed what it actually was!
After "Holly Jolly Secrets," pretty much anything the Ice King has ever done that was meant to be funny could be called this.
The scene of PB pushing Lemongrab onto the floor and making him cry becomes cringe-worthy when it's revealed later on that Lemongrab thinks of PB as his mom.
Marceline standing outside in the show, staring into the window in "Holly Jolly Secrets II" is a punch in the heart now that it's revealed that Marceline was once a daughter figure to the Ice King, and had to watch him lose his mind.
At the end of Too Young, Lemongrab leaves on his camel, looking miserable and sulky, muttering to himself as he returns to his home. Then we find out later that he has no friends, or anybody, back home.
Jake joking in "Jake the Dad" that his kids are grown up. But in "Puhoy," when BMO reminds him of this, we see him struggling not to cry.
There is such a thing as an enchiridion. This also counts as Bilingual Bonus. Enchiridion is a Greek word (although spelled differently) meaning, among others, 'manual'. It is also Latin (spelled as written in the episode) for "handbook."
PB's chalkboard in "Too Young" describes and demonstrates the Big Bang. Also counts as Freeze-Frame Bonus.
Princess Bubblegum instructs Marceline "begin playing triplet quavers in mixolydian mode," which is just full of advanced music lingo known only to those who have studied music at a college level.
During the video of the fight between Marceline and Finn in "Daddy's Little Monster," Jake gets hurt and shouts "Ow, my hippocampus!". The hippocampus is the part of the brain that contributes to forming long-term memories, so Jake was right when he said "That explains why we got amnesia."
A chalkboard in "Goliad" shows a molecular line diagram for the molecule carbon trioxide. Not much of a Genius Bonus if you paid attention in high school chemistry.
"Ignition Point" borrows heavily from "Hamlet". The voice Finn and Jake hear through the vents is reciting lines from the play.
Girls Need Role Models: The Fionna and Cake episodes are much more dedicated to supplying morals that the younger girls of the audience need to hear, with the first about not needing a guy and the second about dealing with self-proclaimed bad boys.
Princess Bubblegum is a deliberate subversion of all the useless pretty damsel princesses that girls grow up with. She doesn't care for romantic advances and prefers science and her kingdom over love.
So Marceline's dad just ate her fries. Doesn't seem like it's bad enough to refuse to talk to him ever again, right? But in "Memory of a Memory" we see the fries he was eating were in a broken-down abandoned diner after the apocalypse. Chances are food of any kind was scarce and teenage nonvampire Marceline probably needed them more than her deathless father...
Basically everything about the Ice King after "Holly Jolly Secrets".
Related to the above: In the Fionna and Cake episode, Cake wore the Ice Queen's tiara and Fionna knocked it off Cake's head, yelling, "No! You might catch her crazy!" As "Holly Jolly Secrets" revealed, the Ice King's crown caused him to go crazy. Now the whole episode is a Fan Fic by the Ice King... so he knows to a certain extent that he is not the person he used to be. Similarly, at the end of "The Eyes," Ice King, after spending the entire episode spying on Finn and Jake to learn the secret to happiness, ends the episode with the line "I'm...still not happy". Sad enough in context, but after all the revelations concerning his past, it starts to seem like he is subconsciously aware of what he's lost, on some level, and cannot be happy because of it.
"Too Young," viewed as the creators of the show intended, is an episode that goes from funny to heartwarming to rather dark. However, when viewed from the failed experiment Lemongrab's point of view, it's depressing.
The Royal Tart Toter's insanity is Played for Laughs in his first appearance in "The Other Tarts," and his cameo in "Holly Jolly Secrets Part II." Where do we see the Royal Tart Toter next? In "Princess Cookie," in a mental hospital.
An upset Lemongrab left at the end of "Too Young," and came back a year later. He mentions that his castle has no citizens. According to Word of God, the only people in his castle are his servants, and he has no friends. When Lemongrab goes home in "Too Young," he's returning to a life of near-total isolation.
Even though Lemongrab is really hateable in it, "Too Old" makes it painful to rewatch "You Made Me!" After the events of "You Made Me!," Lemongrab becomes a happy, adjusted person who has a wonderful friend, and a creator who worries about him and cares about his feelings. Watching "Too Old" after watching "You Made Me!" is going right back to square one, back to Lemongrab's angry, isolated, self-loathing, sad, friendless, lonely life- and Princess Bubblegum reprimanding him and bullying him when he ends up royally sucking at his job.
Ash selling Hambo to that witch. It was revealed in "I Remember You" that Simon Petrikov gave child Marceline Hambo when she was scared and alone in the post-apocalyptic wreckage. Just when you thought you couldn't think of Ash as more of a dick.
While Marceline's journal song is already pretty harsh, given that she's admitting to being lonely, hating being immortal and pushing people away so that she won't get hurt, but there's one line in particular that becomes unbelievably heartbreaking after watching "I Remember You":
Marceline:(singing) They don't know what it's like to live forever and forget who they even are...
Similarly to the above, Marceline's line about not having friends was a Tear Jerker to begin with...and then it's revealed that she grew up in an irradiated, post-apocalyptic wasteland. She probably didn't have friends because she and Simon were the only survivors around.
In her very first appearance it's established that Marceline has more than one dwelling place in Ooo. It's later revealed that she kept moving house in the past to avoid the Ice King and the painful memories he induces.
In "All Your Fault," it is revealed that Lemongrab has suicidal thoughts. Remember the scene in "Too Young" where he literally walked out of a window? Or the scene in "You Made Me" when he purposefully fell out of one? Yeah.
All of the scenes of Lemongrab and his brother loving each other are really cringe-worthy to watch now that Lemongrab has partially eaten his clone, and is now abusing him verbally.
A lot of people forget Tom Kenny. This is the same guy who played Spongebob. And now we have Simon Petrikov's final tapes, and the Ice King crying in "I Remember You." Tom Kenny really is an amazing actor. This is an actor who is almost exclusive known for comedic or petty roles, and yet he plays the most tortured and complex character in the whole show. The final moments of "Holly Jolly Secrets." As it turns out, Tom Kenny can not only reduce you to helpless laughter, but helpless tears, as well.
Through all of his ham, you really have to give Justin Roiland props for "You Made Me." The scene of Lemongrab running into the night wailing in sadness would not have been nearly as effective without his heartfelt acting. Also, his performance as "Lemonjon" in "All Your Fault." Even though the pitch of his voice was lowered significantly, his performance was still wrought with such genuine emotion. The brief speech given by Lemongrab 2 in Too Old is very affecting.
Andy Milonakis sounds youthful and likable whenever he appears as NEPTR.
Hilarious in Hindsight: Many people complained that "Incendium" felt short and should've been a two-parter. Turns out that the season 4 premiere continues directly from where "Incendium" left off, so the two episodes may as well be considered parts of the same episode!
This image◊ becomes a lot more relevant after watching "Lady and Peebles".
Justin Roiland, (Lemongrab's voice actor,) apparently predicted the plot of "All Your Fault" (and parts of "You Made Me") two years before the episode aired, in a strange freestyle rap from his podcast. It's... uncanny to say the least.
In the Japanese dub, Finn is voiced by Romi Park, who is Korean-Japanese and speak both languages as well. And he cannot understand Lady Rainicorn. Even more hilarious (and ironic) she also voiced by another Korean-Japanese actress, Bong Young-hi.
Lemongrab's very first line in the show was "This castle is in unacceptable condition!" In the episodes "All Your Fault" and "Too Old," his castle is in VERY unacceptable condition.
Hollywood Pudgy: Fionna. She was designed to be "chubby cute" according to her designer, Natasha Allegri, and certainly appears to be thicker in the concept art, but she looks a lot slimmer in the show◊. In concept sketches by Natasha Allegri◊ and Rebecca Sugar◊, she looks genuinely plump, but she looks very average in the show.
"Heat Signature" revolves around Finn and Jake being tricked far too easily into thinking they've become vampires.
"All Your Fault" was about the Lemongrabs (and all of their children) almost starving to death because the Lemongrabs made all of their food into children. even when they were given help, they still messed it up. It took PB removing the Candy Life formula from their heads to make them stop.
Incest Yay Shipping: The Lemongrabs, fullstop. The revelation that the two are brothers surprisingly heightened the desires of Lemongay shippers!
Alternatively, some see this simply as clones and relationship companions, but not necessarily siblings.
It Gets Better: The show can be kind of a slog at first, throwing you into the deep end of completely random humor. It takes a while to build up any real sense of the characters.
It Was His Sled: It has become general knowledge that the Ice King used to be a human named Simon Petrikov, and that he raised Marceline for a time. Something that took time to built on in the show.
Lemongrab. As hateable as he is, you kinda feel sorry for him. Now, in "Too Old," he is in complete Woobie, Destroyer of Worlds territory when taking everything, including what was revealed in the second video game, into account.
Magic Man. It was heavily implied in "Sons of Mars" that he was a relatively decent person once, and loved his girlfriend dearly. But when she died, he turned into a near-sociopath, inflicting horrible chaos onto people for his own amusement. As much of a bastard as he is, the scene of him caressing her picture, saying her name softly shows there was humanity in him once.
Donny. Throughout his episode, he went from a jerk to a nice guy. Then, he was bullied back into jerkdom, and revealed at the very end that he still cares about Finn and Jake, even though his life requires him to be a jerk to everyone.
The Pup Gang from "You Made Me!". Even after all they've done, they didn't deserve getting electrocuted that many times.
The Door Lord. Yeah, he stole everyone's stuff, but did he really deserve to get the shit beaten out of him and get tied to a chair?!
Clarence. He killed Ghost Princess, but like Achilles, he fell in love with her as she died and killed himself over it.
Marceline/Bubblegum is highly favored within the LGBT community, as well as their genderswaps.
As of "You Made Me!," so is Lemongrab/Lemongrab clone, and again, with their genderswaps.
But not so much as of "Another Five Short Graybles" and "Too Old."
Princess Cookie to the transgender community.
Love to Hate: The fanbase takes a real liking to the dreaded, unfunny, dark, murderous and with No Sense Of Humour terror that is the Lich, mainly because he took such a drastic turn from the show's usual silly tone. The base was intrigued with him long before he made his first full (non-cameo) appearance in season 2. The love got boosted when he cleverly outsmarted Finn in the season 4 finale by exploiting his heroic traits and using them against him.
Possibly Marceline in "Marceline's Closet." Up until she tried calling Finn's house to see if he was there, she had no idea the duo were in her closet. They started laughing at their taped message and she realized right away they were there, and started doing things like recording an awkwardly emotional song, using the bathroom, and taking a shower. The ending cements this to make Finn and Jake paranoid as retribution for breaking in her home in the first place. She is very much a Troll.
"In Your Footsteps": Doubly subverted with the bear. At first it seemed that the bear was getting close to Finn so that he could steal his identity. Then it's revealed that no one actually thought the bear was Finn, and the bear just wanted to be more heroic by emulating Finn. Finn gives the bear the Enchiridion so that the bear can get along on the way to becoming a hero. HOWEVER... it turns out that the bear is a henchman for the Lich, and he was after the Enchiridion all along... so that he could give it to the Lich.
The Lich in, well, "The Lich": Having spent the last two years watching Finn and learning how he thinks, he manipulates Finn by possessing Billy and getting Finn, who idolizes Billy, to steal the jewels from the Crowns of Ooo. After Finn puts the jewels into the Enchiridion and the Lich's presence is revealed, he knows that there is one of two options: Finn will either submit and give him the book, or try to destroy it, forming the very portal the Lich wants. Either way, the Lich wins.
Lemongrab is starting to appear like this, after the summary of "You Made Me!" revealed that Lemongrab peeps on Princess Bubblegum and the Candy People while they sleep. LEMONGRAB WATCHES YOU WHILE YOU SLEEP.
Lemongrab has got nothing on ''The Freak Deer''. It's a bizarrely human-like deer that licks people. It doesn't talk or anything it just licks people.
It only licks people made of sugar. Finn and Jake , despite being helpless for quite some time, were not abducted and included into the globbish mass of candy people in its lair. what it did to them is still Nightmare Fuel, but not sexual. It was storing them and keeping them as food.
Ice King has been this since the pilot, thanks to his tendency to kidnap princesses and force them to marry him.
Cartoon Network seems to be trying to turn Manfred the Pinata's "WHAAAAAT?!" into this.
Various users on Adam Muto's formspring kept asking "Who would win, The Lich or Marceline's Dad?". He got tired of the questioning and responded with something involving "The Lich's dad". This was likely caused by someone on the wiki posting that Marceline's Dad may be able to defeat The Lich.
"Hey everybody look! Look at this book I found about eating babies, they just sit there while you eat them". "I don't know, but I'm going to go eat one right now". note based on the rather casual response of the fox in Jake the Dad after finding a book about a fox who eats babies.
Me-Mow crosses it when she poisons Jake and won't give him the antidote unless he kills Wildberry Princess and then, while talking in her sleep, she lets it slip that once Jake kills Wildberry Princess, she plans on double-crossing him and letting him die of the poison anyway.
Ricardio crosses it when he tries to cut out Princess Bubblegum's heart with broken bottles of glass after spending most of the episode earning her trust. And if he didn't cross it there, he certainly did so when he tied Lady Rainicorn in a knot. At least he had a goal to accomplish with cutting out Bubblegum's heart; hurting Rainicornwas just to show off his new body.
Even for being a Jerkass Woobie character as Lemongrab with very mental problems, some fans think that he definitely crossed it in "Too Old". Even though Lemongrab still left his clone alive and kept him alive on a machine, Lemongrab constantly abuses him physically and verbally. Not only that, he attaches shock collars to all of their 'sons' and forces them to entertain him after he became a Fat Bastard. Then it gets even worse that when Lemongrab 2 thinks his twin has finally came to his senses when he heard Lemonhope's song, Lemongrab mercilessly eats his twin (again) and orders their boys to kill Princess Bubblegum, Finn (who is too distracted by the relationship blues to care), and Lemonhope.
If the Lich hadn't crossed it before, he definitely crossed it when he murdered Billy and possessed his body to manipulate Finn and Jake. Shortly after that he than tries to wish for the extinction of all life in the universe which just as monstrous, if not more.
In "Earth And Water" we learn that Flame King crossed it shortly after Flame Princess was born when he had her thrown in the forest to die just because he was somewhat worried she would usurp his thrown when she got older.
More Popular Spin-off: Adventure Time began as a lesser known, if memetic, short from Random Cartoons, as mentioned on the main page.
Anything BMO says can cause large amounts of Squee:
BMO:Who wants to play video games?
The humming noises that the Lemongrabs made when they nuzzled their faces together in "You Made Me."
Plop-Top's little "song." So cute!
"James Baxter the Horse" has James' catchphrase as an in-universe example, being instantly able to cheer up anyone who hears it. The episode revolves around Finn and Jake trying to create their own version so that they can do the same thing.
Lemongrab. Even when his situation and backstory are genuinely Played for Drama, Nightmare Fuel, or a Tear Jerker, he's still a screaming, Large Ham with the voice of an awkward teenager. The sad thing is that even when he's written to be serious, we can't take him seriously because of his rather unfortunate voice.
The same applies to the present-day Ice King to an extent in "I Remember You," but it's mitigated by hearing his past self speak in "Holly Jolly Secrets".
Finn's battle cries in earlier seasons, back when his voice actor was going through puberty.
Ice King's giant pile of boogers in "Holly Jolly Secrets". Just... eugh.
Projectile vomiting into people's faces. There were two instances- Jake puking in Finn's face in "Storytelling," and Lemongrab puking in Peppermint Butler's face in "Too Young".
Finn and Jake spitting food into each others' mouths in "Jake vs. Me-mow."
Barb the spider giving birth in "Web Weirdos".
Magic Man's house. The decaying rat in the corner, the mold on the ceiling, and the giant puddle of snot on the floor.
"Five More Short Graybles" has Finn and Jake sticking their thumbs into a Surinam toad that's giving birth. Eeuuugh.
"Mystery Dungeon" has Lemongrab contemplating eating the Ice King. The Ice King is an old, saggy man who probably smells bad. And Lemongrab wants to eat him. DISGUSTING. Later in the episode, Lemongrab eats a pie out of a giant rat's mouth.
Some of the Lemon Children in "All Your Fault" are rather grotesque. Special mention goes to the giant, fat, bush-looking thing that was drooling on the floor and saying "Blauh, blauh" repeatedly. Also the green, fat one who licked Jake's hand. Perhaps the grosses part of the episode was the scene in which newborn Seed-Wad vomits all over himself, and the vomit drips down his little chest and all over the table and floor.
The video Ice King sends Finn and Jake in "A Glitch is a Glitch" made just about every viewer throw up. What's worse is when Finn and Jake eat Finn's hair.
Morbidly obese Lemongrab in the episode "Too Old." Euuugh.... No....
To say nothing of Lemongrab 2's state...
No Yay: In the middle of "I Remember You" Ice King trying to kiss Marceline when she accepts his hug, which she's squicked out by. After seeing "Simon & Marcy," it's clear from her point of view, she might see this as Wife Husbandry.
Painful Rhyme: The song in "Evicted" tries to rhyme 'old' with 'code'.
Marceline: I'm not mean, I'm 1000 years old/And I just lost track of my moral code.
Pandering to the Base: Fionna and Cake started off as a one-shot non-sequitur episode used to further establish the Ice King as a crazy loser, and to mock the concept of fan fiction, and the fanbase, in general. But after Fionna and Cake aired, the fans loved the genderbent characters seriously and unironically. Some fans feel like "Bad Little Boy" was unnecessary, and was only pandering to this part of the fanbase, though the audience-mocking subtext is the same.
This promo for "The Lich," which features the Lich's horrifying face zooming in on you. This could air during any commercial break between the first airing of "I Remember You" and the first airing of "The Lich," giving your screen a face full of Lich before you know it.
The Ice King's backstory.
Periphery Demographic: Little kids, older kids, teenagers, and even adults all are attracted to this show.
For having a wide range of female characters with different body types, making fun of pick up artists, the morals of Fionna and Cake episodes, and a scene where Marceline and Finn beat down Ash (Marceline's abusive boyfriend) because of a Stay in the Kitchen comment, the show's got a huge feminist following.
Unfortunately this fits the bill with Adventure Time: Explore The Dungeon Because I DON'T KNOW as it is a repetitive, boring and very unimaginative Gauntlet clone, which is especially bad considering the series it's based on.
"A Glitch Is a Glitch" has a few. For example, at the beginning of the episode, Finn and Jake are using a computer paint tool to draw a drawing of Ice King covered in snakes and spiders. Guess what attacks Ice King at the end of the episode? Huh? Erm, no, but you were close. There's also the fact that the Glitch eats the code for Princess Bubblegum's chair, which disappears in the very next scene. Also, Jake's arm claiming that PB's hand is cheating on him makes sense once you realize that PB made out with her hand (though you might not want to dwell on this too long).
Ice King and Marceline's pasts and their connection to each other seems like a Shocking Swerve the first time through, until you rewatch old episodes and start noticing the loads of hints and foreshadowing dropped.
The Reveal in "Earth And Water" certainly puts a lot of scenes involving Flame King in a whole new light.
Ron the Death Eater: Princess Bubblegum has received a lot of flack from fans over some questionable acts. She does occasionally lapse into some morally ambiguous areas, but certain parts of the fandom unfairly make PB put to be a monster who apparently eats her own subjects For the Evulz.
FlamePrincess sometimes gets this, especially from Fubblegum supporters. Although it's now been revealed that she isn't evil and doesn't want to be, and that she has a pretty good Freudian Excuse for her early behavior, there are still those who persist in portraying her as merely a destructive psycho. Seems to have died off after she and Finn broke up at the end.
"Fubblegum/Bubblefinn" (Finn/Princess Bubblegum) and "Farceline/Finnceline" (Finn/Marceline) show up often in forums. Lately we have "Bubbline/MarceBubble/Marcegum/etc." (Princess Bubblegum/Marceline), though it's usually shortened to Pb/M.
Bubblegum and Marceline is also known as Sugarless Gum.
Lemongrab/Lemongrab clone is known as "Lemonzest" or "Lemongay," but without much surprise, it is not called "Lemonparty". In the comics, the name for the shipping of the genderswapped "Lady Lemongrabs" is "Lesbilemon."
Ship Mates: Some who were reluctant to ship Princess Bubblegum/Marceline because they didn't want Finn to be alone decided to welcome the Finn/Flame Princess ship with open arms.
Some fans also came up with the 'Fubbline' solution, a threesome between the trio. When Flame Princess came along, a few others evolved to 'Flumbaline'. The fanbase adapts, alright.
Ship Sinking: The show has never shied away from development of romantic story arcs, with Finn growing up and having to deal with emotional feelings like any other teenager does.
The Princess Bubblegum & Finn ship is a core, central pairing, and one where the potentially romantic relationship between Finn & Bubblegum has been sunk and refloated numerous times.
It appeared that the episode "Burning Low" had Finn get over Bubblegum for good.
One episode after Flame Princess breaks up with Finn, he regains his crush on Bubblegum and arranges to accompany her to a Castle Lemongrab dinner. It does not go well. Bubblegum eventually snaps after Finn persistently bugs her to try and solve the problem with a juvenile prank, and Finn learns that their age difference isn't just a number, it is the reason they are fundamentally incompatible in a romantic sense.
Finn/Bubblegum was given yet another revival in "Breezy". As his arm is being repaired by Breezy, Finn imagines Bubblegum in the place of Breezy while the lines "Who calls to my heart", and "My hero arise, let love be your guide" are sung over the scene.
The Finn/Flame Princess ship was sunk in "Frost and Fire" when Finn manipulated Flame Princess into fighting the Ice King, causing her to break up with him, though there was some reignited hope for them in Earth and Water with the two continuing to be on good terms, only to be completely dashed in The Red Throne by Cinnamon Bun of all people, admitting his feelings for Flame Princess.
The Lemon-Gay ship didn't sink- it burst into flames. First, the Lemongrabs were revealed to be brothers. Then, Lemongrab tried to eat his brother. After that, Lemongrab tortured his little brother mercilessly, leaving him disfigured and unable to walk. And finally, Lemongrab devoured Lemongrab 2 again, possibly killing him for good. This is probably the worst way a ship could die.
There may be a fourth candidate in the rising Finn/FlamePrincess ship. And now that Nat has just designed Flame Princess's gender-swapped counterpart, Flame Prince... welp, The Great Mushroom War might as well be occurring in this fandom.
In "Lady and Peebles," Ricardio clearly has a sexual interest in Princess Bubblegum, saying he wants the "full package" and to be "united as man and wife".
Tree Trunks has a crush on Finn. Tree Trunks, by the way, is a very old small elephant woman, while Finn is a young boy.
Also, the fact that that the Ice King ships Fionna, Finn's Distaff Counterpart, with himself. This is made even more troubling when it's revealed that Fionna is in fact a character in the Ice King's fanfiction about Finn and Jake.
Although this was in a platonic, comforting way, Princess Bubblegum leaning close to Finn and putting her hand on his leg in "Burning Low." Out of context, it's just uncomfortable.
The nature of the relationship of the two Lemongrabs. It's entirely possible that they're twin brothers, or a couple... or both.
The episode "Another Five Short Graybles" confirms that the Lemongrabs are brothers.
Prince Gumball's (Ice Queen's)song in "Fionna and Cake", and really any song that was written by Rebecca Sugar on the show (except the Fry Song and "I'm Just Your Problem," of course, which can be real downers).
Tainted by the Preview: "The Suitor" was a base breaker from the previews cause many people were worried about some sort of Relationship Sue development this was not the case as A) PB had no interest whatsoever and B) the episode was a complete deconstruction of Dogged Nice Guy.
For some, it was kind of cathartic seeing Lemongrab in "Mystery Dungeon" having all of his bodily fluids profusely squeezed out of his head as he screams for his mother and almost dies. Some thought he had this coming after what he did in "You Made Me."
Also, Tree Trunks doing something very simple: scolding Lemongrab for being an annoying, selfish asshole and telling him, "You'd better be nice!" He lowers his head and apologizes in a much quieter tone. You go, Tree Trunks.
Ash getting punched out by Simon in "Betty". He didn't even know who he was. He just wanted to take his flying carpet.
The fact that apparently there is no taboo against incest in the Lemon Earldom. The promo art for "Too Old" shows two lemon brothers making out with each other. This creepily helps to justify the gay subtext between the two Lemongrabs as more plausible.
Lemongrab's entire story arc in regards to Princess Bubblegum and his children becomes this when one realizes that Princess Bubblegum physically and emotionally abused Lemongrab, who later went on to physically torture and berate his own children. This ties into the (sometimes true but still misleading) stereotype that people who were abused in their childhoods always grow up to be abusers to their own children. It's especially jarring because "All Your Fault" seemed to subvert this stereotype by portraying both Lemongrabs as loving, doting parents.
Jesse Moynihan, a writer on the show, stated that he used a real-life autistic person, Stephen Wiltshire, as partial inspiration when writing the character Lemongrab, who comes across as Ambiguously Autistic and is incredibly mean-tempered and the butt of many jokes.
While the show is fairly groundbreaking in its frank and often realistic and often very sympathetic portrayal of people who are mentally ill, it is a fact that most of their mentally ill characters either exist to be scary, comic relief, or both. Ice King's insanity is often played for laughs, Lemongrab's autism and other issues paint him as a frightening villain or a laughable idiot, Princess Cookie was extremely violent and was taken to a mental hospital, and the Royal Tart Toter existed just to be a non-sequitor.
Well... Princess Cookie was taken to the mental hospital for trying to commit suicide. Beforehand, Princess Bubblegum was going to throw PC in the dungeon but changed her mind (probably after Jake explained the situation).
Lemongrab mauling his twin to the point of deformity and abusing him afterwards is rife with this.
Lemonhope is the only lemon child that has a more "normal" looking appearance (i.e. he's more human-looking, even compared to the Lemongrabs themselves). He has a knack for music (with the harp anyway) and is shown to be gifted enough that Princess Bubblegum immediately wants to take him to the Candy Kingdom to enroll him in a school for gifted children. When the other lemon children are freed from their shock collars, instead of trying to escape with Finn, PB, and Lemonhope, they help the group escape with the prodigy lemon child so that he may return and save their kingdom, while the lemon children themselves all stay behind, with their now very angry lemon father. Not only does this give Lemonhope some serious early Purity Sue/Marty Stu vibes, but reeks of unfortunate implications because Bubblegum chose (well-meaning or not) the only "normal" child that was special enough to leave a horrible place that all the children were abused at.
The 3D animation in "Guardians of Sunshine" (all animated by one CalArts graduate) and the fourth-dimensional bubble animation in "The Real You."
The portal from "The Lich."
The perspective drawings of Lemonjon looking down and walking to the Candy Kingdom, and the incredible animation of Lemonjon exploding and dissolving into thousands of little lemon candies.
In-universe, Princess Bubblegum's wax dummy melting in "The Creeps." It's even on the Nightmare Fuel page here for that reason.
All of "A Glitch is a Glitch."
Wangst: Marceline and Lemongrab sometimes lapse into this. When Marceline is upset, she writes angsty songs and plays her bass guitar. When Lemongrab is upset, he screams, cries, and blames everyone around him for his distress.
Finn and Jake, frequently. "Heat Signature" comes to mind. This has dwindled as time has passed.
Ice King in "Hitman."
Lumpy Space Princess in "The Monster," when she abysmally attempts to apologize to the villagers, and ends up insulting them instead.
Finn completely in Frost and Fire. To quote The Cosmic Owl "You blew it."
What Do You Mean, It's for Kids?: Despite the PG content and rather mature overtones once in a while, Adventure Time is still very much meant for kids. The writers do a very good job of leaving in enough to imply, but never any literal words to be inappropriate.
The relationship between Princess Bubblegum and Marceline. Whether intentional or not, the relationship can be interpreted as a friendship that went sour, or a romantic relationship that went sour.
It's strongly implied that the Lemongrabs are a gay couple, because they love each other, live together, have no problem with hugging or nuzzling while they're naked, and have children together. But it's never been explicitly confirmed by anyone working on the show, or any of the characters. Then confirmed to be brothers really sank that ship...and then what Lemongrab does to Lemongrab 2? Yeeaaahhh its like they wrote it purposely to sink this gay couple interpretation.
The goblins in "The Silent King" most definitely count as this, particularly Gummy.
The Royal Tart Toter. That poor, poor man. Although he's actually pretty damn happy and upbeat, he's completely insane, blind, and deaf. He's still completely dedicated to his job of delivering the royal tarts, even though he's in no condition to, and he's in a mental hospital.
Baby-Snaps. As a child, he was in an orphanage. When Princess Bubblegum showed up to cheer up the kids, she asked Baby-Snaps what he wanted to be. He said cheerfully, "I want to be a princess like you!" Princess Bubblegum giggled, thus starting Baby-Snaps's Start of Darkness and Sanity Slippage. Baby-Snaps went crazy and started taking hostages in the kingdom in order to get Princess Bubblegum's crown. He was later chased by guards, and he blissfully fell off a cliff to avoid being captured. He survived, and ended up in a mental hospital, where he was crowned "Princess of the Grass Kingdom."
Princess Monster Wife. She was created by the Ice King from the stolen body parts of his favorite princess. The princess was hideously deformed, but a genuinely sweet, damaged character who needed a hug. Although the Ice King constantly told her she was beautiful and wonderful, Finn and Jake and the penguins were continuously repulsed by her appearance. She spent most of the episode crying and questioning her own existence, and she eventually killed herself for the good of the other princesses, by returning their body parts to the rightful owners. It is implied her spirit lives on, though.
Prince Huge. He had been transformed into a giant, hideous frog, and the only way to break the spell was with a kiss. So he went around kissing everyone, trying to break the curse. Everyone he encountered assumed he was trying to eat them, and he garnered a reputation for being an evil monster. After learning of his backstory, it's impossible to NOT feel for the guy. His story had a happy ending, though- Finn turned him back into his normal form, and all is well.
To a lesser extent, the squirrel from "Up A Tree" qualifies. He admits that the other animals who live in the tree pick on him for wanting to be a flying squirrel. During his conversation with Finn in the jail cell, it's hard not to feel sorry for him.
The Magi creature from "Little Dude" qualifies. He hid himself underground so he wouldn't accidently curse anyone. It's revealed the poor guy had an abusive father who kept calling him a bad wizard.
The Lemon Children. They all almost starved to death. One of their brothers is dead. Their dads are the Lemongrabs, and the one who actually loves them is tortured by the other one. Poor little things.
Braco has caused a strong reaction from the fandom. Not only was he another suitor for Bubblegum who wasn't Finn and was actually very likable on his own, but Bubblegum's dismissive treatment of him throughout made a lot of people sympathetic for him.
The problem with Braco is that, while he acts the part of the Dogged Nice Guy, he's also a walking personification of Entitled to Have You, obviously under the belief that just because he's been nice to her and done a few favors for her, she should love him in exactly the way he wants her to, regardless of her say in the matter. He also gleefully ignores how A.) PB has made it abundantly clear that she has no interest in being in any romantic relationship whatsoever and B.) Finn, no matter what you may think of him, has done far more for PB and the Candy Kingdom than Braco could ever hope to; if that's not enough to be automatically deserving of Bubblegum's affection, then she certainly has no obligation to Braco for what little he's done.
Lemongrab 2 is seen by a large portion of the fanbase as a woobie, especially after "Too Old" where he was horribly disfigured and in very bad shape, as well as being horribly abused by his older brother before finally being eaten whole by him while making a passionate speech to his children.
Flame Princess in "Earth And Water". Especially after we learn that part of the reason she was locked up for most of her life was because Flame King thought she would usurp his throne. He was so afraid of this happening that shortly after she was born, he had her thrown out into the woods to die.
Shoko from "The Vault". If her past is to believed, her parents sold one of her arms for a computer, and then abandoned her at a dojo. Then, she's forced to steal from Princess Bubblegum, who is probably her one and only friend, and ends up falling into a radioactive river, mutating into a horrible monster before curling up under a tree to die. And to top it off, her spirit remains restless for possibly thousands of years until she's able to return the amulet she stole from PB by acting through Finn's subconscious.
Even Finn, considering all the things that happen to him, from getting beaten up all the time, to losing romances, and of course possibility the only human remaining, yet he still keeps an unbreakable happiness.
The unbreakable happiness is just recently, well... breaking.