I'm always interested in how Satan is portrayed in films, but only if he isn't a big red bloke with horns or a sinister looking guy with slicked back hair and a goatee, because that's really boring.
In Zulawski's 1972 film The Devil, he is portrayed as a sharp faced sandy haired little man with the unerring ability to be everywhere at once. He is a stirrer and a wheedler and rather pathetic, especially when it becomes apparent that he is totally reliant on human beings to do his work for him ('he's a petty clerk, they won't let him have any bigger tasks'). He is short and slight and easily pushed around, bursting into tears when he doesn't get his own way. He carries a gun and has a weakness for interpretive dance, but isn't any good at it.
Eventually, he gets his cock cut off while raping a nun and, in death, turns into a big black dog.