A Necromancer is a thin, monkey-like creature with predominantly black fur, except for the fur on its arms, legs, and its long, prehensile tail. Its arms and tail are yellow, its legs are green, and its hands and feet are black with sharp, red claws. It wears small, yellow and red bracelets and anklets, as well as a dark red tunic over its upper body. Most notably, the Necromancer wears a mask that covers most of its face, save for its ears and glowing, yellow eyes.
This mask is mostly red with white edges, black and yellow markings in its sides, and a jagged mouth. It also has two twisted, salmon-colored horns on its top and a long, bent protrusion resembling a fiery beard sprouting from the mask's chin. Its Heartless emblem is on the forehead of its mask, and it carries a staff known as the Spell's Relic+ for its magic, usually holding it in its tail.
The Necromancer's name references the art of necromancy, a form of black magic involving the manipulation and interaction of the dead for the purpose of divination.