Shoko was a black haired girl with green skin who died many years before the events of Adventure Time. She makes her first major appearance in "The Vault" where it is revealed that she is one of Finn's past lives. After her death, Shoko appears to Finn as an amorphous ghost in "The Creeps", "King Worm", and "The Vault".
According to her, she was mutilated and abandoned by her parents at a young age, which resulted in her taking the path of a common criminal. She supposedly only has one arm because her parents sold her right arm for a computer before dropping her at a dojo to give her fighting skills. Her parents never returned to the dojo; thus, Shoko was left without any parents or guardians. She later befriended a tiger and the two began to roam the lands of Ooo in search of work.
In her former life, she was a humanoid who was notable for having one arm, the other being removed and left as a stump. She had long, black hair about knee-length, lime green skin and bright yellow eyes similar to that of Farmworld Finn. In addition, she gains a mechanical arm from Princess Bubblegum like the Farmworld boy. Her outfit consisted in a gray dress and flats and a teal scarf. She is also equipped with a dagger that is typically strapped to her chest.
Shortly before her death, Shoko was knocked into the radioactive river beneath the Candy Kingdom. This mutated her, turning the girl into a slug-like creature with two arms, the second grown back through her mutation. Shoko retained this appearance even as a ghost with minor differences. Her spectral form had light grayish-blue ethereal skin with scale-like lumps and long, green seaweed-like hair. Her scales are light blue, her irises are black, and her pupils shine red. Interestingly, her appearance differs from the most of the other Ghosts in the series, who are all less colorful and more smoothly shaped. Even her ghost shape appears mutated. Her design is also similar to a Japanese style ghost.
Due to her parent's neglect and her lack of a proper upbringing, Shoko had a warped view or morality and common sense. For example, she seemed genuinely surprised when Princess Bubblegum told her that parents are responsible for taking care of their children. She was also indifferent about criminal activity, such as stealing, as long as she would be paid with coin. This was seen when she casually took on the job of stealing Princess Bubblegum's amulet. In addition, dialogue between her and the Bath Boy Gang leader suggested that she had taken lesser, but still similar jobs in the past.
Although Shoko cared little about what was right or wrong, she was generally very kind towards those close to her, such as her tiger. Shoko also began to show signs of regret over befriending Princess Bubblegum for the purposes of stealing her amulet. This was to the point that Shoko became conflicted on stealing the amulet. She even began to tear up when the Princess Bubblegum presented her a mechanical arm for helping her in the Candy Kingdom. Despite this, Shoko's fear of the Bath Boy Gang forced her to carry out the theft of the Princess's magical amulet. However, years after her death, Shoko was able to redeem herself by making Finn return the amulet on her behalf.
Despite only having her left arm, Shoko was a skilled fighter. This was seen when she quickly defeats a Bath Boy Gang member while carrying buckets with little trouble. She accredited this to her time training at a dojo during her youth after her parents left her there and never came back.
Shoko is also a capable thief as she was hired by the Bath Boy Gang's leader to steal Princess Bubblegum's necklace. For the job, she cleverly decided to befriend the Princess rather than attempt to steal the item outright. Shoko also seems to easily work her new mechanical arm, even with the short amount of time she possessed it.
As a ghost
Shoko became a ghost shortly after she fell into a toxic river that once flowed through the Candy Kingdom when it had yet to be contained or neutralized. Upon being immersed, a newly formed Gumball Guardian attempted to rescue her, but the waste proved too noxious for their bodies within the seconds they attempted to fish her out. Shoko was mutated and later emerged as a long amorphous creature. She then crawled up to a hill, in front of a tree sapling, and died. On that very hill, Finn's future tree house grew, where her corpse was in the branches, holding Princess Bubblegum's amulet.
As a ghost, she resembled the form she took during her death. Shoko first appeared as a large slug-like creature with long, green hair in the Castle with Finn as he was hiding. Shoko came out through the wall and gazed at Finn as her hair slowly filled the room. Finn broke through the wall to the next room to escape from her, thinking that she had killed all of his friends and that she was after him too. He later found out though that the party was just a prank by Jake and that Jake had no clue who she was, that he must have imagined it. He then decided to forget the experience by putting it "in the vault."
Shoko, in her ghost form, made a minor reappearance in "King Worm" when Finn unleashed his subconscious fears to escape his dream. This reveals that although Finn put the memory of her "in the vault," he is still subconsciously afraid of her or at least of his memories as her. In "Sky Witch," Princess Bubblegum passes what seems to be a painting or picture of Shoko as a ghost in Maja's house.
As a ghost, Shoko was able to phase through walls, which was preceded by a ripple effect on the space and a humming sound. Her green hair grew to fill the library that Finn was hiding in, as if trying to reach him. She seems to be able to take possession of items, or produce hallucinations.
- Shoko and Farmworld Finn both are missing their right arm. Regular Finn later loses his right arm in "Escape from the Citadel," but regains it in "Breezy." Later, Shoko regains her arm too, due to the exposure to the toxic river.
- "Sky Witch," what seems to be a framed picture or painting of Shoko's ghost form can be seen in a pile of stolen objects, while Princess Bubblegum explores Maja's storage room. Seconds later, in a different shot, Shoko's painting's expression suddenly changes, seemingly becoming more creepy or menacing. This was speculated to be due to the painting being sentient, possessed, or otherwise animate. However, artist Derek Hunter has confirmed that this was a mistake due to two different drawings being mixed up somewhere during production and that only one of them was meant to be shown in this scene.
- The robotic arm that Princess Bubblegum gifts to Shoko has similarities to Finn's robotic arm seen in "Finn the Human," "Jake the Dog," "King Worm," and "Puhoy," as well as Finn's vision of himself in the future in "Mortal Folly."
- This continues the trend of alternate versions of Finn, except Fionna, having artificial right arms.
- Also like Finn, Shoko had an animal partner, except it was a normal white tiger, instead of a magical dog. The tiger was stated offscreen by Jesse Moynihan to be a past life of Jake.