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, appeared outside in the daytime without protection, and had no bite mark on her neck. The older Marceline during the fry incident also does not have a visible bite mark, although the left side of her neck was not visible in that scene.

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, not progress in age to become older in appearance.

Source of Marceline's physical traits
Marceline's physical traits (pale bluish skin, pointed ears and fangs) might not be the result of her vampiric nature, which would explain why she had that appearance as a child. Ash, a being who is not a vampire but a wizard possesses various vampire-like qualities in his appearance, including fangs, gray skin and pointed ears. With his existence and knowing he isn't a vampire, it could be possible that Marceline is a similar being to Ash which she was before she became a vampire.

Further, 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.

Pendleton Ward at one time supposedly stated that Marceline was a human before the Mushroom War and only became a vampire to survive it. (Note that we currently can't find a source to prove Pen said this.) Even if this was true at one time, the writers could have retroactively changed the storyline since then. If so, one could suspect that Marceline was never human and was born a humanoid being with her current appearance, only becoming a vampire later in life when in her teens.

Fries
In the "fries" memory, both teenage Marceline and her father wanted to eat fries, something that vampires presumably would not be interested in, since they only eat blood and shades of red.



Marceline's mother
Nothing is definitively known about Marceline's mother. A picture on the wall of Marceline's House might depict her. This picture has been seen in her house in "Memory of a Memory" and several previous episodes.

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.