Mysterious Stranger (Fallout: New Vegas)

Mysterious Stranger is a perk

Effects
If the last target at the end of a V.A.T.S. sequence has 150 health or less, there is a 10% for the Mysterious Stranger to appear. He will then finish off that target using his unique .44 Magnum.

Behind the scenes

 * The Mysterious Stranger wields a revolver and wears a fedora and overcoat, like a protagonist of 1950s film noir.
 * There were several unfinished drafts of a book by Mark Twain titled "The Mysterious Stranger," in which the title character claims to be Satan's nephew, and which contain various references to the number 44.