- “Silence sinner! Prepare for an eternity of horrible pain!”
- ―Satan, "Treehouse of Horror XI"
The Devil, also known as Satan and Lucifer, is in charge of Hell. The Devil sometimes manifests as Ned Flanders, but has often manifested in other forms, such as the Herman lookalike fawn in season 2. His manifestation in Ned Flanders is sometimes considered as a separate character, Devil Flanders. He often appears in visions or dreams. Whenever Charles Montgomery Burns has a near death experience, Satan tries to get Burns there, but continually fails. He also appears in the music video Deep, Deep Trouble after Bart ends up with him. Bart was ordered to be reincarnated but as a snail.
A giant advertisement statue in the image of the Devil was seen in "Treehouse of Horror VI" where it came to life with the other advertising characters and was convinced by Bart Simpson to destroy Springfield Elementary School.
The Devil also appears in "Treehouse of Horror XXII", he is referred to as being in charge of God, and when Ned Flanders says "Can this get any worse?" then it turns out that Maude Flanders' ghost is sleeping with the Devil, The Devil is husband of Maude Flanders' ghost.
In Ned's dream, there were devils representing things that Ned feels threatened by, which looked like Moe Szyslak (representing alcohol), Hyman Krustofsky (representing Judaism), Mr. Burns (representing consumerism, or himself), Waylon Smithers (representing homosexuality), Homer (representing himself) and Richard Dawkins (representing atheism).