Finn the Human (voiced by Jeremy Shada in the TV series, Zack Shada in the original pilot short ) is a human boy who loves nothing more than going on adventures and saving the day. He wears a hat that covers his extremely long flowing yellow hair. He is prone to exclamations and outbursts including "Mathematical!" and "Algebraic!" When Finn was a baby, he was abandoned and subsequently adopted by Jake's parents, Joshua and Margaret, as detailed in "Memories of Boom Boom Mountain". Considering himself a hero, Finn has a lust for adventure and swore long ago that he would help anyone in need, but being so full of energy, he has trouble in situations that require him to do tasks other than fighting. After initially having an unrequited crush on Princess Bubblegum, Finn began a relationship with Flame Princess that lasted until the events of "Frost & Fire". In "Billy's Bucket List", it is revealed that Finn's birth father, Martin, is alive, and is trapped in a dimension known as the Citadel, which is a prison for the most dangerous criminals in the Multiverse. The actions of Finn and Jake, along with those of the Lich, cause Martin to be released; Finn soon learns that he is a petty criminal, and in the ensuing chaos, Finn loses his right arm, but later regains it in "Breezy" only to lose it again in "Reboot" before being fitted with a mechanical arm which can transform into many different weapons. The grass sword curse later re-manifests itself in the sixth-season finale, "The Comet", wherein Finn also learns that his spirit is the same as the catalyst comet.