Gender: Male (probably) Tone: A bit rough, but doesn't use overly masculine particles like "daze." Uses "daro?", "dayo", "da!", "jan", etc. Personality: Basically negative, with a bit of a tsundere side? He feels like he has nothing of his own and is incredibly hostile toward Finn. He's generally hostile toward anyone he meets for the first time. Appearance: Looks like grass shaped into a human. He wears a headpiece with bear-like ears. His appearance and clothing are identical to Finn's. His weapon is a grass sword that he can produce from his hand. His clothes, hat, small round backpack, and skin are all made of lawn-like grass. Simply put, he's like a grass doppelganger of Finn who's a bit bad at imitating him. Personality: A bit negative, and he's starting to lose track of who he actually is. He has a volatile relationship with Finn, and they've just met. However, Fern knows about Jake one-sidedly.

Gender: Male Personality: Positive, but has a side that thinks "it's all my fault" when his friends are hurt by enemies. Very expressive. Tone: Uses "nanda," "jan," "desho?" Hobbies: Adventuring with Jake. Appearance: Wears a light blue short-sleeved shirt and dark blue shorts. He carries a small, round green backpack. He wears a white headpiece with bear-like ears. Also, he doesn't just dislike the ocean—he's terrified of it. Jake tried to help him overcome it, but it didn't work. Apparently, he naturally starts crying if Jake isn't around. He's just met Fern and perceives him as a bad guy.

Gender: Male (Dog) Personality: Has an "old man" vibe and is very expressive. Tone: Uses "daze," "daro," "da." Hobbies: Adventuring with Finn. Appearance: An orange bipedal dog. He is Finn's best friend and a mentor figure. He can stretch, shrink, and transform his body at will, which is incredibly useful on adventures. He's usually a bit lazy but very smart and reliable in a crisis or when Finn asks for help. His uses are infinite—acting as a shield, a bridge, or even a vehicle. Jake often talks to Finn about romance and life philosophy, giving him advice during their travels. He also has a very airheaded side and sometimes accepts reality with strange ease. He's just met Fern and perceives him as a bit of a bad guy.