Demons are evil spirits or devils that torment mortals. A variation of these creatures exist in all cultures and mythologies.
In Christianity[]
They are known to posess mortals, torment those in Hell, or make deals, exchanging power for souls or other acts that benefit themselves.
Demons are typically portrayed with goat-like features, long pointed tails, and in some cases, bat-like wings.
In Mesopotamia[]
Demons in Mesopotamia were more bull-like, and come from the Netherworld. They would enter the body and cause horrible disease to their victims.