The cloak appears as a black leather cloak that is smooth to the touch. When it is placed on a dead human or demi-human (elf, dwarf, gnome, etc.) the corpse comes back to life but deformed, and maybe special powers at the DM’s discretion.
The cloak only works once on a corpse. The resurrected creature must wear the dark cloak at all times or they will instantly die when it is taken off, never to be resurrected again. If the current occupant of the cloak dies again or takes the cloak off, its powers may be used on another corpse.
The Mortician’s Cloak is said to be imbued with a powerful necromantic magic that is activated when it is worn by a corpse. The magic works by restoring the body to a state of animation and jump-starting its metabolic processes.
As the cloak envelops the corpse, it emits a bright, pulsating light that infuses the body with the necromantic energy needed to revive it. The energy flows through the body, awakening its cells and tissues and restoring their vital functions.
As the body comes back to life, the cloak continues to channel necromantic energy into it, providing the sustenance needed to maintain its animation. The reanimated corpse will continue to function as long as the cloak is worn, but once the cloak is removed, the body will return to its previous state of death.