Mystery's disguised form is a white dog with black paws. He has red eyes and a red and black spiky mane of hair on his head. He wears a pair of tiny, gold-tinted glasses, as well as a dog collar with a question mark on it.
His true form is that of a large kitsune with six tails in "Ghost". As of "Freaking Out", he now has seven tails. It is unknown why this change has occurred; however one theory is that as he is a Kitsune, and Kitsune gain a tail every 100 years, he may have simply aged between the two events. In the fourth episode, Mystery assumes his kitsune form and gains two more tails over the course of the video.
After being mortally wounded by Shiromori, he transforms into a black corrupted kitsune with green paws and flames flowing out of his backside. He has nine tails, each with a yellow eye, a stripe running down to a white tip, and, with the exception of the rightmost white tail, black fur with green accents. From left to right, the stripe of each tail is a color from the rainbow spectrum plus white and black. His mouth is a jagged grin with green gums and sharp teeth, his left and right ears are red and green, respectively, and he has three eyes — the left and right both have red sclera and white irises, and the middle one is a sickly green with a double yellow-red iris. His glasses are also jagged and his dog collar tag has morphed into an interrobang. In this form, he's referred to as "Murder Mystery".
Little is known about Mystery, although he's shown to be very loyal and protective of his friends. He might be greedy or has a lot of appetite, as seen in Ghost where he and Vivi devastate the eaten guard and make a big sandwich.
However, a flashback to ancient Japan reveals this wasn't always the case. In "Hellbent", Mystery is seen sitting on top of a tree littered with the remains of samurai armor, and snickering at Mushi when she encountered him. These flashbacks present Mystery in a dark, sinister fashion, implying that he may have been far more malevolent in the distant past.
In the present day, Mystery is Vivi's pet dog and the mascot of the Mystery Skulls paranormal team alongside Vivi's friends. In "Ghost", it's shown back when the four explored the cave, Mystery seemed uneasy. When the gang split up, he was supposed to go with Vivi, but instead chose to follow the two boys for unknown reasons.
When Arthur becomes possessed and pushes Lewis off the cliff, killing him, Mystery removes Arthur's arm — freeing him from any further possession. The arm itself remains possessed, as seen in "Freaking Out" where the arm makes a cameo at the beginning of the video.
As the van breaks down, Mystery and his friends enter a haunted mansion where Lewis tries to kill Arthur. As the group sprints away to escape a pursuing Lewis, Mystery pauses to view a painting behind him where they all enter a cave. As soon as the team enters, they spit up. As Mystery sneaks up on behind them, he sees Arthur being possessed and push Lewis off a cliff edge. The scene zooms out and the picture behind Mystery reveals a picture of himself in his true form with glowing red eyes grabbing Arthur's possessed arm. Mystery rejoins the group in a dash to the exit of the mansion as Arthur pulls Vivi away from Lewis, all 3 quickly jumping into the van to escape the haunted house.
While Arthur is searching for Lewis, he seems to daydream or hallucinate Mystery turning into his true kitsune form which frightens Arthur. When Arthur snaps back to reality, he freaks out and falls to the ground, surprising Mystery who appears rather confused by Arthur's sudden reaction. As soon as Arthur passes out, Mystery catches a small familiar petal falling near the van — a chilling sign that Shiromori is still hunting him down for his blood.
While Arthur is driving kate into the night, he slowly warms up to Mystery who in return shows affection for Arthur. As soon as Arthur is being chased down by Lewis, Shiromori slams into the van and cuts Mystery's face with her shears, causing him to bleed and spur on Shiromori's blood lust. After the van crashes, Shiromori walks up to Mystery while there are flashbacks of Mystery fighting Vivi's ancestor, Mushi and giving his blood to a flower that looks similar like Shiromori. As she can cut Mystery, she is hit by Vivi with a bat. As soon as Shiromori gets back to her senses, she sees Vivi as Mushi and freaks out. Shiromori is enraged, knocking down Vivi, and is about to cut Vivi as Mystery turns into a kitsune.
As Shiromori was about to cut Vivi, Mystery bites into his paw and draws Shiromori away with his blood. As Vivi watches him drawing her away so that she can get away, she decides to fight Shiromori as soon as Mushi gives her power to Vivi. Vivi duels Shiromori for Mystery, who is in awe and shock over Vivi's newly-discovered abilities. A soon as they're fighting, Shiromori cuts Vivi's face and Mystery jumps in, throwing her into the truck.
Shiromori sees Mystery protecting Viv like Mushi did, causing her to mad and making giant roots from her arm. Mystery grabs Vivi and puts her on his back and they begin to fight Shiromori. Vivi jumps off from Mystery and smashes the roots with her ice powers, weakening Shiromori. As soon as Vivi was about to finish Shiromori off, Mystery jumps in, gesturing Vivi to give his old friend mercy. Vivi agrees and walked away with Mystery. Still angered by Mystery, Shiromori attempts to strike Mystery until Vivi jumps in and takes the hit, slashing her in the abdomen. Mystery's heart began to tear apart, different colors are pouring out of his heart while growing another tail. He charges at Shiromori but gets knocked down. Vivi grabs the bat and knocked Shiromori's heart out which causes her to wither away. Mystery then grows another tail and the colorful liquid began to pour out of Mystery's heart even more.
Mystery faints and Vivi cries, thinking that he has died. However, Mystery's eyes suddenly glow green while his fur turns black, and colorful lighting swarms around him causing Vivi to be hit into a van, Arthur's arm mechanically crazy, and giving Lewis a headache. As soon as the team groups up, they see Mystery has undergone a frightening metamorphosis into a twisted version of the kitsune, Murder Mystery.
Earlier, it is shown that Arthur's possessed arm grabbed Mystery's broken heart and it starts laughing.
In "Hellbent", it is revealed that Mystery once fought a swords-woman who bore a striking resemblance to Vivi, most likely an ancestor. He may have been aware the Vivi is a descendant of Mushi. This might indicate that during the ancient times, he became allies with Mushi and decided to live with the Yukino family.
There is not much known about Lewis's and Mystery's relationship. Before Lewis died they were members of the same team and seemed to be friends. Prior to the fourth episode, it seems Lewis was unaware of Mystery's origins or true form, even in the event of his death when Mystery forcibly removed Arthur's arm after Arthur pushed Lewis while possessed.
Shiromori and Mystery seem to know each other, though why and how is currently unknown. Mystery seems to be afraid of her and is being hunted down by her for some reason. Shiromori is most likely hunting Mystery to get power from his blood, as suggested by a flashback where Mystery's blood drops on a flower. As Shiromori can grow flowers linked to people by magical means, Mystery's blood might have given Shiromori her power over plants. This would also explain why she is so desperate to harm him.
In "Hellbent" his blood is revealed to have dropped on a particular flower, likely in the aftermath of his fight with Vivi's ancestor. This is implied to be part of the reason why Shiromori is hunting him, though the connection of the flower to Shiromori is yet unknown.
In "The Future", Mystery and Shiromori's relationship is revealed to be fairly complicated. Shiro still wants Mystery's blood while Mystery is forced to fight her even though he clearly doesn't want to hurt her in order to protect Vivi.
A swordswoman heavily implied to be Vivi's ancestor, Mushi and Mystery once fought in the distant past, most likely to protect her people from Mystery. Yet when Shiromori confused Vivi for Mushi, from Shiromori's perspective, Mushi was defending Mystery, implying that somehow, Mushi and Mystery became allies.
- Overpowered Magic:
- Metamorphosis: It can change shape and appearance like all Kitsunes. Mystery transforms and re-transforms skillfully, due to the circumstances seeming to do so for safety reasons, because Shiromori wants his skin and blood. To the point of almost never revealing his supernatural nature.
- Create life: Mystery created Shiromori with a few drops of blood and a flower, giving it a humanoid form.
- Conferring powers: Mystery can confer powers, as with Shiromori in the past with some of her blood.
- High intelligence:
- Communication and Multilingual: Mystery can speak and probably knows Japanese and English. Artsy said he could know more languages than that.
- Super strength: We see him in '' The Future '' when he throws Shiromori away with his jawbone.
- Improved agility and speed:
- Heart: Judging by the images in "The Future", a mysterious red heart connected to Mystery directly influences his mystical form. In periods of stress, the heart can burst and release strains of a liquid-like energy corresponding to the number of tails, apparently causing Mystery to lose control. Seeing Shiromori and Vivi significantly hurt, for instance, enraged and distressed Mystery due to the strong bond he shares with them, making him emotionally unstable and vulnerable to ???'s possession.
- Mystery's design is inspired primarily by Mystery Ben's original character. His character is also inspired by Scooby-Doo from the American media franchise of the same name.
- Despite Mystery's resemblance to Mystery Ben's avatar, Ben himself has stated that he relates more to Arthur.
- Mystery's name alludes to the video creator's online handle (Mystery Ben), and the name of the paranormal investigation team as well as the group whose music the videos are based on (Mystery Skulls), and to the fact that he hides his true nature from the others (thus being a mystery himself).
- It is heavily hinted that Mystery may hail from Japan. His favorite instrument is the Japanese taiko drum. His favorite show is GeGeGe no Kitarō (an anime about Japanese yökai) and his favorite game is Ōkami (which also takes place in an ancient Japanese setting and centers, fittingly enough, on a wolf deity). His true form is a kitsune, and he was being hunted by Shiromori. This was confirmed in "Hellbent".
- Mystery's age is listed as "...'7'" on his official profile, implying that this is not his real age. Being a supernatural creature, he is likely far older than a normal dog could be, possibly even hundreds of years old. "Hellbent" partially confirms this, as Mystery is seen alive in ancient Japan.
- According to yokai folklore, a kitsune grows a new tail every 100 years. Since Mystery's kitsune form has 7 tails, it can be inferred that his real age is 700 years old. The problem with this theory comes from his 'heart' (most likely a Hoshi no Tama, widely known as an orb that houses the kitsune's soul). As seen in The Future, moments of extreme distress opens new gashes in his 'heart', which increases his number of tails. It can be inferred that at the start of his life, he had one tail, thus bringing him up to the current number with eight gashes in his 'heart'.
- Mystery's flower that appears in "Freaking Out" is a red lotus. Red lotuses often represent ascension, enlightenment, and rebirth. His flower is also noticeably much larger than that of the other members of the team, hinting at his mystical abilities and powerful "aura".
- Mystery's favorite food is listed as "...'chicken'" which some think may be a joke regarding Arthur being a 'chicken', since Mystery bit off his arm.
- It's confirmed that Mystery can speak and he likely knows Japanese and English. Artsy stated he might know even more languages than that.
- Mystery's height is 3 feet and 3 inches.
- His larger form in The Future is likely ???'s doing, seeing that at the end of the video, the arm resembling ??? is grabbing what is likely Mystery's heart. Also, it is shown that Mystery's eyes glow green just as Arthur's eye did when he got possessed. He also breathes a green smoke or mist, possibly being because of ???.
|Characters in Mystery Skulls Animated|
|Protagonists||Arthur • Vivi • Mystery|
|Antagonists||Lewis • ??? • Shiromori|
|Minor characters||Dead Beats • Painting Ghosts • Pepper Family • Lance • Mushi • Galahad • Duet • Chloe • Rooster • Yukino Family|