|Occupation||Prince of Darkness|
|Voiced by||Sean Kiely|
In contrast to the biblical Satan (also known as Lucifer, The Devil, and Beelzebub), who is portrayed as a quick-tempered, powerful, supernatural entity that is the personification of evil and the enemy of God and humankind. In Leo & Satan however, he is portrayed as a child-like buffoon who appears to only enjoy eating pancakes with sugar on top, playing with his best friend Leo, or other equally child-like activities. Satan also exhibits somewhat of bipolar episodes; such as knocking the controller out of leo's hands for no reason at all in Battery Catastrophe or yelling "I DON'T FUCKING KNOW!!" at Leo in Trash Hazard.
Satan's relationship with Leo borders on an almost nurturing tone, as seen through Satan's cast iron attitude towards wearing socks, but almost directly contradicts this with periodic episodes of terrifying actions. Satan is very child like with his mannerisms and understanding of the world, but possesses a very powerful front of power. Even Satan's best intended gestures usually cause trouble for Leo. This subtle mix of innocent catastrophe and demonic power provide adequate room for story building.
Satan also cares deeply for Leo, as he is seen crying with Esquire after accidentally slicing Leo's upper torso into pieces in Trash Hazard. While still being capable of terrifying Leo at regular intervals.
- When Satan says "You asked for it!" in the title sequence after he comes through the trap door from hell, suggests the notion that he was called upon by Leo.
- This suggests another interesting theory, that Leo calls upon satan when he wants to play.