Mister Sandman

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

With the Mister Sandman perk, when you are in Sneak mode, you have the option to silently kill any human or ghoul while they're sleeping. All Mister Sandman kills earn bonus XP - which amounts to 50 experience points per kill on any difficulty.

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 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.

Bugs

 * Prior to patch 1.0.0.15, it was possible to use the perk on children. This would not kill the sleeping child, but the experience would still be gained, allowing for unlimited EXP. The bug returns in Fallout: New Vegas.
 * 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.
 * Sometimes, dead victims will still speak when you steal nearby items, scolding you for your theft. There are no consequences for this, though, it's just creepy.
 * Sometimes during the murder, victims will wake, and alert everyone to your presence.(This happens if you are sneaking)
 * 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.