Demons

Demons are a species and/or metaphysical construct in the Monsterverse.

Appearance and Physiology
Demons have no physical form of their own while on Earth; they must find a body to inhabit in order to interact with humans. In Hell, they can be pretty much anything. Most have preferred forms while in Hell. Most of them try look like the damned souls that are in Hell in order to further torment them.

Most demons' original bodies are locked away in the deepest part of the Pit. They could theoretically earn them back by doing things to get kicked out of Hell and put back on Earth... but they're usually having too much fun to care.

Origin of Demons
The oldest and most senior demons are Fallen angels that gave in to temptation while in Heaven. The oldest demons supported Lucifer (yes, that Lucifer) and were thrown out of Heaven along with him.

Lesser demons are usually human souls who gave in to torment while in Hell and decided to become tormentors themselves to escape the pain.

Demons are usually assholes.

Demon Weaknesses

 * Demons will die if they're out of a body for 7 hours while on Earth
 * Must rely on humans to find hosts
 * Hosts prone to physical decay after a certain amount of time
 * Demons themselves prone to mental decay after a certain amount of time on Earth in a host

Demon Strengths

 * Ability to psychologically push humans (e.g., "Satan told me to do it")

Notable Demons

 * Sitri
 * Merai (half-demon)