Tyrannosatan (Demonic Imperator Tyrannosatan) is the final boss of Deathsmiles. This powerful demon appears when Jitterbug attempts to open a portal to the real world, coming through the portal and eating Jitterbug, forcing the Angels to fight him. After he loses half of his health, he loses his body and Jitterbug falls from it. Though Tyrannosatan is ultimately destroyed, he still survives as a ghost, becoming the familiar of Supe in the second game.
In the Mega Black Label update of the game, if you fulfill the conditions Tyrannosatan will possess Jitterbug after being defeated, becoming the true final boss Bloody Jitterbug.