Moloch, alternatively called Mo-san or Mossan, embodies the sin of Wrath and personifies Violence. He manifests physically in two distinct states: a diminutive chibi form resembling a small brown cow-like creature clad in a black-and-white cow-print t-shirt, sporting small white horns (one encircled by a gold band) and a tuft of black hair; and his true demonic form, unveiled in Hell, which transforms into a massive, muscular bull-like minotaur bearing slit-like pupil-less eyes and a perpetually menacing expression.

Typically quiet, Moloch harbors an explosive temper. He channels anger through physical actions over words, favoring violent resolutions to conflict. This preference led him to counsel fellow demon Azazel to kill their human contractor if displeased. Summoned without subsequent utilization, especially when violence is withheld, sparks frustration. His rage ignites most intensely at the concept of humans consuming beef, a reaction stemming from a summoner mistakenly offering beef curry instead of a required human sacrifice.

Contracted to the occult detective Akutabe, Moloch operates from within the detective's agency. Fellow demons, including Azazel and Beelzebub, recognize him as exceptionally violent and fear his anger. Akutabe acknowledges his superior combat prowess compared to other summoned demons, though the practical application of his specific ability "Violence" remains undefined. During his service, the angel Sariel confiscated his grimoire to Heaven, causing his death.

Following this demise, a younger brother designated Mossan II (or Moloch II) appears. This successor shares his brother's bovine appearance but exhibits an even more volatile temperament. Mossan II once uncovered a secret about Akutabe, provoking the detective's severe retaliation that induced a heart attack in the demon.

Trivia notes include Azazel's nickname "Mossan" for him. While his original form is formidable, his chibi version is occasionally mistaken for a bull plush toy.