As most vampires, she reveals that it's the color red she likes to suck out of various things, and blood is only appealing because it is red. Like a traditional vampire, she is vulnerable to sunlight and is capable of turning into a bat, varying in size. It was also revealed in "Return to the Nightosphere" and "Daddy's Little Monster" that her dad desired Marceline to be the next in line to rule the Nightosphere, however she does not want to take up the position. She is a survivor of the "mushroom war" as stated by series creator Pendleton Ward, and in "Memory of a Memory" a trip into Marceline's mind shows her as a child wandering around the outskirts of a destroyed city. Marceline is the only person to ever address Princess Bubblegum by her first name, Bonnibel, in "Go with Me?"." In "What was Missing," it is implied that she and Bubblegum may have had some sort of relationship in the past. Furthermore, later on, it was revealed that Marceline has some sort of relationship with the Ice King in the past. While Marceline has many things in common with Finn, in the episode "Go with Me?" and "Daddy's Little Monster" it was stated that Marceline likes Finn for being 'just' himself, and nothing more or less.Marceline is described wandering the Land of Ooo have made her a fearless daredevil. She has a mischievous personality and is not intimidated by anything. Marceline is described by Finn, in the episode "Henchman", as "a radical dame who likes to play games". She loves to play pranks with Finn. She was very emotionally attached to her teddy bear Hambo; in the episode "Memory of a Memory", after Ash sold it to a witch, she was furious and broke up with him. She is also very independent, and she often feels alone as depicted in "Marceline's Closet". It is easier for Marceline to express her feelings through music, as seen with "Daddy Why Did You Eat My Fries?" and "I'm Just Your Problem." She expresses most of her feeling when she sings a private song based on 500 years of her journal entries in the episode, "Marceline's Closet."Marceline has really long and dark hair, she usually has her axe guitar with her. She never seems to walk on the ground before, but only floats when she travels, moves, sleeps, and other things. In the episodes Marceline is in, she is always with Finn and Jake.
Marceline wears different outfits in most of her appearances. According to Pendelton Ward, her clothing changes from episode to episode because "girls own more than one outfit". For example, she wearsblue jeans, red boots, and a light gray tank top in her first appearance. In the episode, "Henchman", she is seen wearing a short, dark gray dress, where the top is ripped and there is a dark pink band going across it.Marceline and her father (Hunson Abadeer) has trouble accepting one another. Through the episodes "It Came from the Nightosphere", "Return to the Nightosphere" and "Daddy's Little Monster", this concept was further depicted and explored when her father taken back the family inheritance, the Axe's guitar, which symbolize her father unwillingness to accept her daughter's decision which kick started the troubling relationship. Later on, Marceline was tricked by her father to takeover the Nightosphere. Marceline wasn't willingly understand about feeling she has with her father but end both understand their feeling for one another.MarcelineTheQueen (talk) 19:56, October 18, 2012 (UTC)
Marceline and The Ice King seem to have nothing in common at start, but it was later, in the episode "I Remember You", that it was revealed that they had some sort of past relationship before, right after the Great Mushroom Wars. It was Simmon, the Ice King, before he lost his mind to the power of the crown, that gave little Marceline Hambo, the teddy bear, to watch over her. This kind gesture made the Ice King a long-time, very close friend to Marceline.