According to Shoko herself, 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 off 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, who was eventually confirmed to be one of Jake's past lives, and the two began to roam the Land 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 roughly knee-length black hair, lime green skin, and bright yellow eyes. In addition, she gains a mechanical arm from Princess Bubblegum like Farmworld Finn. Her outfit consists of a grey dress, flat shoes, 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 her into a slug-like creature with two arms, the second grown back through mutation. Shoko retained this appearance - with minor differences - even as a ghost. 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 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 parents' abuse and her lack of a proper upbringing, Shoko had a warped view of 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 showed signs of guilt over befriending Princess Bubblegum for the purposes of stealing her amulet. She began to tear up when 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 amulet. 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 falling into a toxic river which once flowed through the Candy Kingdom. Upon being immersed, a newly formed Gumball Guardian attempted to rescue her, but the waste proved too noxious for their bodies within the few seconds they attempted to fish her out. Shoko was mutated and later emerged as a long amorphous creature. She then crawled up a hill and died in front of a tree sapling. That very sapling grew into Finn's future tree house, where her corpse remained in the branches holding Princess Bubblegum's amulet.
As a ghost, she resembled the form she took during her death. Shoko first appeared in the Castle during the episode "The Creeps." Having the appearance of a large slug-like creature with long, green hair, Shoko came through the wall and gazed at Finn as her hair slowly filled the room. Thinking that she had killed all of his friends and that she was after him too, Finn broke through the wall to the next room to escape. Though he later found out that the party was just a prank by Jake and that Jake had no clue who she was. Due to this, he came to the conclusion that he only imagined it. He 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. 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.
In "Come Along With Me," Princess Bubblegum briefly envisions Finn's robotic arm as the one she gave Shoko, which causes her to concede Finn's argument against war with Gumbaldia.
- "The Creeps" (debut)
- "King Worm" (cameo, dream)
- "Sky Witch" (pictured)
- "Come Along With Me" (Nightmare Juice and Princess Bubblegum's flashback; cameo)
- Shoko and Farmworld Finn both are missing their right arm. Regular Finn later loses his right arm in "Escape from the Citadel," but he regains it in "Breezy" and once again loses it in "Reboot." Later, Shoko regains her arm too, due to the exposure to the toxic river.
- Shoko's mutated ghost form may have been a manifestation of her regret over betraying Princess Bubblegum and stealing her amulet. After Finn returns the amulet to Bubblegum for Shoko, she appears in her normal form as if her spirit is finally at peace.
- In "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.