Occasionally, when incorporeal undead run afoul of the abyss, the chaotic energies warp and transform them into umbraxi. Although a rare occurrence in general, this transformation happens most readily with greater shadows that somehow end up incarcerated upon abyssal layers that are proximate to the Dreaming Gulf. Umbraxi are weightless and have no discernible visible form, their immaterial presence only betrayed by an unusually thick, writhing shadow cast upon the ground below its presumed location.