"Satan can take the form of a beautiful woman, Satan can take the form of a sleek animal. An automobile can be very Satanic. These things can be anthropomorphized into Satan." --Quote by: Anton LeVey's words on his last interview. This page lists the multiple guises that demons use to decieve or intimidate people. Many demons, for example, use the form of an angel to make people with the sixth sense believe they are a true angel.
And accordingly, there form sometimes will match there Order in Hell.
"For such are false apostles, deceit workers, transforming themselves into the apostle of Christ. And no marvel, for Satan himself is transformed into an angel of light.
Therefore it is no great thing if his ministers also transformed as the ministers of rightousness, whose end shall be according to their wor'ks." ---2 Corinthians 11:13-15
A very popular form among demons, especially those who wish to deceive people with the sixth-sense and appear to a summoner who's summoned them as "good and rightous". This form is usually presented to Satanists in the occultic "Religion" known as Satanism to hide the presentation of being a threat.
Mermaid Form and other Forms of Greek MythologyEdit
Common among demons of the Third Order, they're Masters of Witchcraft and are in the forms of Mermaids and "Pan" who are from Greek Mythology.
In the video on the right the demon who says to be "Commander" first says s/he's from "The deepest oceans" which hints the guise of being a mermaid.
An overly common form, this form could be used by a demon to scare summoners and other people who might encounter them. Another form used for this would be there true form, which might be altered also to aid in scaring the summoner or those who encounter them.
Also note that demons can be in the form of animals how they see them. As an example, a demon can turn to the form of a creature that's based on Mickey Mouse to torment a person who liked the cartoon as a child in Hell. See Creature form bellow for more information.
A popular form among demons, this form can look from very beautiful and/or extravagant to ordinary (i.e. looking like a normal man or woman) to being ugly and deformed which can often aid to scare off summoners.
This form doesn't have wings, and is taken by demons of the First and Second Order. Through First Order demons make themselves look like "Gods" of mythology, an exampe would be a demon creating a guise to look like Zeus in order to trick summoner. The Godly form is often tall, scaling over 7 ft. and can be even 15 ft.
Creature Form: Edit
Often taking the form of fictional creatures such as Pokemon and so on, like the above if it's non-human or human-like they often morph into it.
 Howard Pittman, an article about his trip to Hell.