Osiris is a humanoid Stand; with large, muscular arms marked by lines of a vascular pattern; of a thick brow, and fingers capped by rings. It is only revealed from the chest up; mist obscuring a possible lower half.
According to JOJOVELLER, its appearance is a rearranged African traditional picture, with mechanical parts.
Osiris represents the Egyptian God Osiris; related to prosperity and life after death.
Osiris is an Automated Stand.
Soul Removal: Osiris has the ability to take the soul of anyone who loses a bet against D'Arby. More specifically, it will act when the opponent "admits defeat in their heart", which is said to reduce their soul energy to near-zero. If the loser bets the soul of another person, Osiris can take it even if that person is not present or agrees with it.
The souls are compressed by Osiris' fists and stored in a semblance of poker chips, which D'Arby keeps as a collection. A soul poker chip can be split to be used in a game, with all of the parts being equal to one soul. According to Daniel, if the user dies, so does the people from whom he took the souls.