Mister Sandman

Mister Sandman is a Fallout 3 and Fallout: New Vegas perk.

Effects
With the Mister Sandman perk, when the player character is in Sneak mode, the option to silently kill any human or ghoul while they're sleeping is available. XP from killing the target is earned. Mister Sandman kills give a flat 50 XP per kill.

Mister Sandman is performed in sneak mode and by choosing "pickpocket" on an unfortunate sleeping victim. Choosing "pickpocket" pauses the game and brings up a menu with the options to "murder" or "pickpocket". Choose the former to activate the perk. When used, a short murder animation follows with the player character cautiously looking around and slitting the victim's throat, accompanied by a cartoony jingly fanfare.

Possession of a knife or other bladed weapon is not necessary to perform a Mister Sandman kill, even though the kill animation shows the deed performed with a combat knife.

Behind the scenes

 * The "sandman" is a folkloric character who puts sand in the eyes of little children, causing the rubbing of the eyes that is a sign of tiredness.
 * "Mister Sandman" was a song recorded by the Chordettes in the 1950s

Bugs

 * It is still possible to perform Mr. Sandman kills on Kenny from the Point Lookout add-on and Sally from the Mothership Zeta add-on after patch 1.5.
 * It is possible that while murdering the victim, they will wake, stand up and become hostile towards you, however, they will still die after the murdering animation is complete. It seems that when the character being killed starts attacking the player, no damage will actually be dealt by them.
 * In Fallout: New Vegas non-player characters killed by this perk may fall through the floor making it difficult to loot them before they fall.