Lucifer Morningstar

Satan, officially confirmed as Lucifer is the ruler of Hell and is Charlie's father. He can be seen in multiple pictures along with Charlie's mother and Charlie herself in the background of the "Let's Misbehave" clip.

Trivia

 * The apple tucked in the brim of his hat and on the end of his cane seem to reference the story of Adam and Eve where a talking snake (often interpreted as being the Devil) persuades to first woman Eve into eating a forbidden apple, resulting in her and Adam being thrown out of paradise.
 * Satan's character is based on the Devil from Abrahamic Mythology where he is typically portrayed as being the fallen-archangel Lucifer who attempted to conquer heaven in a great war before being cast down to Hell where he became it's ruler and the adversary of God.
 * Charlie seems to have inherited his rosy cheeks, yellow eyes, fangs and pale complexion.