Eira was human, just like Finn, until she met the magic man, who fused her with her cat for fun. Eira was a bounty hunter and grew up an orphan. She was chasing the Magic Man for a reward, and that's how she ended up being half cat. The magic man told her that if she wanted to become human again, she should bring him the head of the vampire king (impossible, it was a joke), but Eira took him seriously. After years of nomadism, She ended up in the Candy Kingdom, hired by Princess Bubblegum to protect the Candy Kingdom or bring her rare ingredients when Fin and Jake weren't available. Now Eira lives in the Candy Kingdom. After going after the mysterious Vampire King, arrogant and self-assured, she failed. Days later, she found out that Marshall Lee was friends with Fin and Jake, her friends too. So she had no choice but to leave him alone for a while. They got to know each other little by little, and although Eira seemed annoyed by the boy and he seemed to enjoy teasing Eira with comments and jabs about her feline appearance and among other things, there's something more between them... They seem to secretly like each other. Eira is clumsy with feelings, She has never had a boyfriend.
