Marceline the Vampire Queen

Marceline the Vampire Queen is a fictional character in the American animated Cartoon Network television series "Adventure Time", created by Pendleton Ward. She is voiced by Olivia Olson in most appearances, by Ava Acres as a child and by Cloris Leachman as an old woman. 
Character.
Marceline is a 1,000-year-old vampire queen. The artistic design for Marceline was created by Ward. Unlike a traditional vampire, Marceline does not need to drink blood to survive; rather, she eats the color red. 
Marceline is a musician who plays an electric bass that she made from her family's heirloom battle-axe.
The character makes her debut in the first season episode "Evicted!" and at first was an antagonist, forcing Finn and Jake from their home. However, as the series progresses, Marceline becomes a close friend to Finn and Jake. 
She was born to an unnamed human mother (voiced by Rebecca Sugar) and the demon Hunson Abadeer (voiced by Olivia's real-life father, Martin Olson). When she was a child, the Mushroom War occurred, and soon after she developed a father-daughter-like bond with Simon Petrikov (voiced by Tom Kenny), who would become the Ice King which was seen in the episodes "I Remember You" and "Simon &amp; Marcy".
In the episodes "What Was Missing" and "Sky Witch" it is implied that Princess Bubblegum and Marceline were in a relationship. In the series finale "Come Along with Me", Princess Bubblegum and Marceline kissed towards the ending and became girlfriends.