Ghoul

Ghouls are undead genies that died in battle, or whose magical item was destroyed. Which are pretty much the only ways a genie can die.

Appearance
Ghouls basically look similar to what they did in their past life, however, they tend to have gray skin, white hair, and washed-out eyes, similar to zombies.

Behavior
Ghouls, like zombies, tend to be able to assimilate into society without any problems.

Powers
Ghouls basically have the combined powers of both genies and ghosts, however, their spells tend to revolve around ectoplasm, rather than what they had in their life. Also, they tend to have contaminant immunity like zombies.