Marceline/Analysis of Marceline's origin

Facts
"Memory of a Memory" shows Marceline aging over time from a young girl in a period, presumably after the Mushroom War, to slightly older (but not as old as current Marceline) during the incident where her father ate her fries to something close to her current depiction.

Young Marceline has the same pale skin, pointy ears and fangs that she has as a teenager or adult. However, little Marceline hops through trees instead of floating over them, appears outside in the daytime without protection, and has no bite mark on her neck. (Although being able to move about without protection could be explained by accounting for a large quantity of fallout in the atmosphere, which could have blocked out a large amount of the ultra violet rays. This is supported by the burning city viewable in the back ground.) The older Marceline during the fry incident also does not have a bite mark. The mark only appears on her neck when her memories of Ash begin.

It is unclear when Marceline became a vampire or how Marceline is able to age over time since typical depictions of vampires have them remain frozen at the age they are bitten and are only able to reverse the appearance of time to give the appearance of looking younger instead of progressing in age to become older in appearance. Andy Ristaino has stated she is "kinda a shape shifter" though, so this could explain her growth. According to Natasha Allegri, she was not bitten when she was 16 or 17.

According to Pendleton Ward, Marceline was probably a vampire before the apocalypse.

Source of Marceline's physical traits
Marceline's pale bluish skin, ears and fangs are all similar to those of her father and could have been genetically inherited from him. According to writer Adam Muto, Marceline's father is more of a demonic creature than a vampire.

Marceline appears to prefer clothing and hairstyles from the 1970's through the 1990's the most. This may be the time frame that she grew up in as an adolescent/teenager/young woman, or she may just like the fashions and hairstyles from those eras.

It could be possible that her status as Vampire Queen means she has more powers than standard vampires (like her ability to change into various monster forms including bats, wolves and tentacle beasts), so she could possibly have become a vampire in the first memory and used special powers to age more, though how she defeated the Vampire King at such a young age is questionable.

There is a possibility that Marceline's mother was a vampire, and the traditional vampire traits like pale skin and fangs were passed from her to Marceline. However, this would not explain why Marceline currently has a bite mark on her neck, but not have one as a child. It could be possible that Marceline gained her immortality only after getting bitten after her teen years, but was technically a Vampire all her life.But it is possible that she was born a humanoid with vampire like features and got bitten turning her into a vampire.It is possible that not all vampires have all her abilities,it could be that powers she has that traditional vampires don't (ex.levitation) could be inherited from her father.

Fries
In the "fries" memory, the teenage Marceline wanted to eat fries, something that vampires presumably would not be interested in, since they mainly consume blood and shades of red, but it could also have been for the ketchup.

In "Henchman," Marceline says that she "kinda likes" the pain she feels when she's in sunlight because it reminds her of when she would scrape her knees when she was a kid and her mom would "patch her up." This both confirms she actually has/had a mother and points out there might be a possibility that she feels love or some type affection towards her mother.

Marceline's Age
Marceline has commented several times that she is "over a thousand years old", which makes one think based upon Memory of a Memory that the Mushroom War occurred a thousand years ago. However, one could argue that Marceline could be fibbing about her true age. However based upon the evidence regarding the Ice King and his origin as revealed in Holly Jolly Secrets Part Two, Marceline seems to be telling the truth about her age. In the episode, the Ice King is revealed to have been a human living in civilization before the discovery of the ice crown, which mutated him into his current supernatural state. As previously revealed by Pen Ward, the Ice King is at least 1,000 years in age, which means that humans and civilization were in existence around 1,000 years prior to the start of the series, to the point that national cultures and boundaries still existed (with him mentioning he found the crown in "Scandinavia", which is an actual location on modern Earth). Marceline's Closet revealed that she has kept a journal for at least 500 years that she was going to write into a song, but Marceline merely said she had "500 years worth", proving that she could have worked on the journal even longer and just wanted to write the song based on 500 years worth of material.

From this, a few possibilities seem to exist regarding Marceline's age and, likewise, the time of the Mushroom War and it's aftermath: In Marceline`s Journal Song she said she does not have friends, but Finn, Jake, BMO, and PB are her friends. She might have said that because she wrote it 500 years ago when she didn't have friends, and had already broken up with Ash. Marceline might be older than she claims she is.
 * The first is that the War did occur a thousand years prior and that the Ice King is older than the 600 previously mentioned, closer to Marceline's age which, as stated, is at least 1000. This would most likely mean he found the crown before Marceline's first flashback, whereas he lived in civilization pre-war and Marceline was first seen during/after the war. This was later confirmed by Pen Ward when he revealed that the Ice King is 1,000+ years old, maybe even a little older than Marceline.
 * Another possibility is that Marceline is lying about her age. As known, Marceline fibs about things all the time to make herself greater than she is, such as riding on giant goldfish in the middle of the daytime. Thus, she may be lying about her age to make herself look greater.
 * In response to the above post, there is no real evidence that Marceline "fibs about things all the time to make herself greater than she is...". Marceline appears to be a person who likes to joke around in an effort to seek out some form of sanity in an otherwise miserable life. She also probably does it to test the personalities of the people she meets to see if she wants to spend more time with them. Take another look at her father (Hunson Abadeer) and the world that she was forced to grow up around (the Nightosphere). Nobody came to her aid to rescue her from Hunson when she was young, and Marceline is not trusting of anyone as a result. What's worse is that the Nightosphere system works against her...and everybody...and she knows this. Her playful, sarcastic personality is a defense mechanism to a place that not only does not care about her, it does not care about itself enough to stop the events that will lead to its own destruction. She most likely knows the horror that is coming, and nobody hears her or sees her at all. Marceline is that highly instinctive person that society continues to wrongfully punish due to the controlling forces set forth by others. It could be that the war scenes depicted in "Memory of a Memory" are her thoughts as a child about what she sees coming to this world down the road. Your memory stores your thoughts as well as actual events. Everyone else around Marceline sees the world as being something along the lines of a utopia with noodle salad, neat little houses in a row, and a promise of stability. Marceline sees a very cleverly designed concentration camp that wrongfully bows down to unnecessary "progress" and has the bulk of the population being dangerously manipulative. This leads to the population enslaving themselves, each other, and her. She sees nothing but a war zone. Marceline was probably born after the GMW (probably either WWII or the mid-1960's hippie/drug era), and she has a pretty good idea about how WWIII (the next GMW) is going to go down. The problem is that nobody will give her thoughts the time of day. This is why she feels, and is, alone. Marceline most likely is neither 1,000 years old, nor is she a vampire. Marceline only feels 1,000 years old. When everyone else ages a year, Marceline ages something like 20 years. This explains the 500 years of journal entries. Hunson, who is notorious for sucking the lifeblood out of Marceline (hence her bite marks), is the being most responsible for Marceline's misery, as well as the misery of many others. However, Hunson was engineered to be the way that he is by the very same societal structure that, in the end, will be destroying everybody...including him. It appears to me that Marceline was born in the mid-1960's (the GMW being the hippie/drug culure of that era), and grew up during the 1970's and early-1980's (the timing of the electronics shown as well as Marceline's hair and wardrobe styles). I think that the Land of Ooo is a breakdown of what must happen to prevent WWIII. This will involve defeating the "science parasite", or the "artificial reality" (enter the intelligent and determined Princess Bubblegum); a return of courage and heroism (enter the adventurous Finn and Jake with their challenges involving the different communities of Ooo); and a return of living with honor, loyalty, and the restoring of the truth, or the "actual reality" (enter Marceline with her independent nature, her high-powered attitude, as well as her absolute refusal to follow in the footsteps of Hunson).
 * There are other avenues of thought on this subject. Marceline's first flashback depicts a war torn landscape. However, we cannot be sure this is the Mushroom War. You'll notice the area looks nothing like the current one seen in Adventure Time. We are led to believe it was the Mushroom War which caused the world to resemble what it's depicted as in Adventure Time. Therefore the war seen in her first memory could either be a different war, or perhaps an earlier stage of/precursor to the Mushroom War. Marceline may have been a normal aging child during this particular conflict. Keep in mind we're told that she was probably a vampire prior to the Mushroom War. We see her as a teenager when she walks in on her father eating her fries. She does not have bite marks. She also appears younger than her present state. The scene is set in a torn up diner. This may still be the set during the same war seen in her first memory. From this we can look at a few things. The Mushroom War itself may not have happened for hundreds of years after Marceline's first memory. In that time she could have been bitten, and therefore immortalized.
 * Another possibility is that Marceline's mother was a vampire, causing her to be born as a vampire. Given that there is no evidence that being bitten is what caused Marceline to become a vampire, this possibility is valid. If we assume that vampires age very slowly, she could still be "a child" by the time of the Mushroom War. It could be possible that the memory Finn and Jake viewed of Marceline as a child shows her when she is 400 years old. If she currently appears to be 18 but is 1000, some simple math (18/1000 = x/400; x= 7.2) shows that if we assume a linear change in what age she appears to be over time, when she is 400 she would appear to be about 7.2, which she indeed does. It is possible that being bitten did not turn her into a vampire, but simply granted her her vampire powers. This means she could have been bitten at any time before she moved in with Ash, but after her dad ate her fries. This possibility suggests that the mushroom war occurred 600 years ago.
 * Because Marceline's father was a demon and not a vampire, it's possible that her physical characteristics of grayish skin, pointed ears, fangs, immortality, and shape-shifting abilities are actually demonic, not vampiric. She appears to not be as intensely demonic as her father so perhaps her mother was only a human and died long ago (she's seen playing by herself with Hambo in front of a house that looks war-ravaged. Her mother isn't around which is evidence that she was perhaps killed). She has a Christian painting on the wall of her house (confirmed to be the Virgin and Christ-child), which doesn't seem like something a demon would want to own, so perhaps she got it from a human, Christian mother. The first time we see her with bite marks is when she's with Ash, so maybe he bit her, turning her into a demon-human-vampire hybrid and giving her powers that she didn't have before. If Ice King is about 1,000 and was only about 30 when the war began, then Marceline's age depends on whether or not demons age slowly (altering her age when she looked like a child during a war), how long her mother had been dead around the time we see her playing with Hambo, and whether or not she and Ice King were witnessing the same war. There isn't evidence that she was aging slowly up until the time she was bitten (the diner ruins in the fry-eating scene look like typical post-apocalypse not magical Ooo scenery) so it's likely she was the age that she appeared to be. If the war that Ice King experienced as a human being is the same one that left Marceline alone in the ruins of her home, then he would only be about 25-30 years older than her. When she was bitten, she could have been permanently frozen in her late teens and remained that way for the next millennium.
 * However, she cannot be born during the 60s; she surely be born during or before the Mushroom War, as shown in the Issue 4 comic, when she is a little girl, she hides in a cave while nuclear bombs are falling from the sky.
 * I respectfully disagree with the above statement. The styles of the appliances in the kitchen in "Memory of a Memory" are reminiscent of the appliances being sold/purchased in the the 1960's.  The checkerboard-style kitchen floor was also common in the 1960's.  Also, many of the electronics featured in the cartoon series existed in the 1970's and 1980's (Atari, Apple, etc.).  Marceline's hair and clothing styles match the era of the 1960's through the 1980's.  Much of what you are seeing in AT is considered to be obsolete now.  You don't see these things any more.  The 1960's seem to be the beginning years of Marceline's life.  The 1970's and 1980's represent her grade school, adolescent, and teen years.  The fact that the 4th comic book shows Marceline hiding in a cave to avoid what appears to be a nuclear war may not be what we think it is.  Keep in mind that a person's memory records both thoughts as well as actual events.  America is definitely a focal point of this story line.  Cleveland, OH is the city skyline shown in "Memory of a Memory".  It appears that Marceline spent some time there as a young child.  I also noticed that Hunson and Marceline had matching red cowboy boots in "Daddy's Little Monster".  This might indicate that the Abadeer family also spent some time in the American south or midwest when Marceline was a little older.  Most people back in the earlier post-World War II era saw the American system as somehow being good, safe, and superior.  If you look around today, the American concept is now being seriously questioned by everyone...especially Americans.  I believe that Marceline, from the time she was a small child in the 1960's, saw through the facade of the American system.  It appears that she saw her fellow Americans as a population trapped in a never ending war of "games theory" that was being orchestrated by others whose intentions were to perpetually control and enslave them all.  Note that this mentality would put her at odds with Hunson, who believes in chaotic evil.  He believes that the world around them needs to be chaotic to achieve order.  Marceline's mentality is that only slavery, not order, is sustained by chaos.  I think she sees Hunson as being "set-up" by those in control, and that someday he will be sacrificed by them and later villified by the population.  Marceline is trying to stop Hunson for his own sake, as well as hers and everyone else's.  She's trying to save Hunson from himself, which he clearly resists.  Sadly, I think that the "memory crack" in "Memory of a Memory" is a skull fracture that Marceline sustained at the hands of Hunson as a child.  This means that Hunson was abusing her because she wouldn't give in to his mind set.  When Marceline tells Hambo, "I'm hurting you because I love you," a common adult phrase of her youth, she appears to be criticizing the adult population of America.  You'll notice she smiles as she says it, though.  It's as if Marceline is acknowledging to the control freaks of the world that she's aware of what they are doing to manipulate the global population.  Getting the population to believe in ridiculous concepts like what she says to Hambo is one of their greatest control tactics.  In Marceline's mind, you don't hurt people that you love, you hurt those that try to convince you that hurting those you love is right.  In "Memory of a Memory", the tanks, the bombs, the military forces with guns, and the blown-up buildings were not present in America during the 1960's...or even now. In Marceline's mind, however, they were all around us...just invisible. The tanks, and such, were Marceline's thoughts and not actual events.  It is as if she was one of only a small handful of people in America that could see the presence of psychological warfare in America at that time...and she was only a young child. I really do believe that this is what we are seeing in "Memory of a Memory".  The images of the 4th comic book are probably an extension of this concept.  In other words, if Marceline could have found a place to hide, like a cave, she would have gone there as a young child to ride out the psychological nightmare she saw going on at home and in American society.  At that young of an age, she would have had few other options. All of the American programs that allegedly protect children usually just abuse and control the children in a different way.  The psychological warfare in America was represented as actual warfare in the 4th comic.  To Marceline, there really is no difference between the two.  You get destruction and death either way.

As of this time, none of these theories can be taken as the true one, thus Marceline's age remains in question outside her own personal words of being "over 1000". However Pen Ward has stated that Marceline is around 1000 years old.