The Nanny Demon is a nanny of another demon and was an inhabitant of the second demon mine who was charged with taking care of Annie, an orphan they had kidnapped. When encountered by Deathspank, the Nanny Demon says that Annie is such a brat that even the demons cannot stand her, and begs him to kill her, as the only escape clause to their contract with Lord Von Prong is death.
The Nanny Demon is considered by many players to be the hardest boss in Deathspank, due to her continuous barrage of projectile attacks and her inconvenient location in the Demon Mines dungeon, where the player does not have access to a working Outhouse to escape the dungeon if they find it too difficult.