Found in The Courier's Mile. This weapon becomes accessible only after first completing The Launch. It is found wedged into a street lamp just to the left as one enters the area.
The weapon's Sneak bonus will be shown as "Activated" when the weapon is equipped in an on-screen message.
It is one of the few unique weapons in New Vegas with the same appearance as its non-unique counterpart.
It may glow blue in dark areas.
Blood-Nap does more damage and has a higher DPS than even Chance's knife, making this an extremely formidable single-handed bladed weapon.
Blood-Nap's Sneak +10 does not act as a bonus, but rather as a raise in Sneak, i.e., if the player character has it equipped when they level up, some perks that require a higher Sneak, such as Mister Sandman, and the player character doesn't have the required 50 Sneak but only has 40, the perk will be available.
Behind the scenes
The name of this weapon is from "dirt nap," a slang term for being dead. The word is iconic for being used heavily in Set's vocabulary.