Despite his small stature, Morubi demonstrates considerable confidence in his abilities, assuming he is the one Demon Tool Soldier made by Eibon that another Soldier mentions as the only one capable of defeating Kilik, although this particular Soldier is far less confident in Morubi's abilities.
While presenting himself to Fire and Thunder like a delightful entertainer, this demeanor seems to be part of his manipulative personality, as he uses his appearance to attract children like Fire and Thunder so that, without such weapons, Kilik Rung is primarily defenseless against the larger, stronger Demon Tool Soldiers.
Morubi resembles a light-colored dog standing upright, with a pointed snout ending in a dark button-shaped nose, paw-shaped hands, and two drooping appendages along the sides of his head that resemble ears. However, these ears end with three dark digits like those fingers at the ends of his hands, making his arms and ears resemble each other.
Each of his legs and arms seem to lack articulation, such that there are no discernible spaces where his arms end and his hands begin or where his legs end and his feet begin. Such limbs accentuate the almost doll-like appearance of Morubi, as he more closely resembles a stuffed animal than an actual dog. Morubi also has a pronounced belly button that extended from his torso. Morubi's eyes have three eyelashes each, and his each of his pupils is in the shape of the Star of David, which also decorates the balls that he juggles.
Morubi dresses in a striped conical hat similar to one worn at a birthday party, a backpack, and a necktie with a choker in the shape of Arachnophobia's logo.
With a push of his belly button, Morubi initiates distractions remiscient of magic tricks, such as birds flying and confetti and stars exploding out of nowhere. Morubi will accentuate such distractions by clanging cymbals, juggling, and breakdancing.
Because Morubi's ears resemble his hands, both in length and the presence of digits at the end of them, it is possible he uses these ears like an extra pair of hands, as seen when both his hands and ears are up in the air followed by the juggling of balls.
Upon infiltrating Baba Yaga Castle as part of a joint team composed of DWMA students and Medusa's Army to assassinate Arachne and destroy her organization Arachnophobia, Kilik Rung and his weapons, Fire and Thunder, dressed in one set of Arachnophobia robes. This odd appearance led Arachnophobia agents to assume the undercover meister was a Demon Tool Soldier. Hence Kilik was led into Tower Two of Baba Yaga Castle and its Demon Tool Soldier Waiting Room. Upon hearing explosions of his teammates destroying the other Towers' Demon Tool Locks, Kilik removed his disguise to prepare to destroy the last Lock in Tower Two.
After defeating multiple Demon Tool Soldiers, including the powerful Demon Tool Soldier 2 and the prescient Insight Demon Tool Soldier, the remaining soldiers not yet defeated by Kilik worried how they could defeat this meister. One Soldier announced that one of Eibon's own creations could defeat Kilik but was surprised that this Soldier was the short, rather childish-looking Morubi. Although barely reaching Kilik's kneecaps, Morubi approached the meister and pressed his own belly button, releasing magic tricks including birds, confetti, and stars while he began to play the cymbals. Fire and Thunder reverted to their Shama forms and dashed to play with Morubi, leaving Kilik almost defenseless as he had to dodge attacks from larger, stronger Demon Tool Soldiers. Seeing his plan was working, the breakdancing Morubi congratulated himself and his "Demon Tool Fun" that would distract Fire and Thunder for a long time.
As one towering Demon Tool Soldier attempted to deal a fatal blow at the dodging Kilik, the meister was saved by Ox Ford, wielding Harvar D. Éclair, who had returned with Kim Diehl wielding Jacqueline O'Lantern Dupré, both of whom had been coaxed out of their Arachnophobia brainwashing by the Morality Manipulation Machine. While Kilik reunited with his teammates, Harvar approached Fire and Thunder, who were enjoying Morubi's dancing, and swiftly and fatally stabbed Morubi in the head with his hand blade, which disturbed all of Harvar's teammates.