Demon-Killing Knife

An ancient knife that was created by the Kurds which possesses the power to kill demons. Ruby obtained it by Season 3. It eventually passes into the possession of Sam and Dean Winchester, who use it as their most common means of killing demons.

Physical Appearance
At first glance, the knife appears to be an ordinary hunting knife with a curved, serrated-edged blade and a wooden handle. However, upon closer inspection, symbols can be seen engraved along the blade.

Powers and Abilities
This knife is capable of killing most demons with a single stab to a vital area, such as the chest or the neck of the demons' vessels. As with The Colt, those killed by the knife briefly glow with orange light, which flickers out as the demon dies. Even non-lethal cuts are excruciatingly painful for demons in the same way that non-lethal cuts from angel blades are to angels.

The knife is also capable of harming the Horsemen War and Pestilence; it was used to cut their fingers off in the episodes they appeared in. It is also capable of killing Hellhounds. Its affect on other supernatural creatures are unknown, as it has never been used against anything else.

Immunity
Very few demon types are immune to the demon-killing knife such as Alastair and the Knights of Hell. However, the knife was capable of inflicting pain on Alastair and the last surviving Knight Abaddon, in fact it was even able to temporarily incapacitate the latter for a few moments. The angels believed the knife could kill the demon Samhain, although he demonstrated an unusual resilience to the knife, finding cuts from it merely somewhat uncomfortable rather than agonizing like a normal demon. Even the first demon Lucifer created Lilith, was frightened by it, but its effects on her and the Yellow Eyed Demon Azazel are unknown.

Angels are completely immune to the knife, as seen in "Lazarus Rising" when Dean stabbed Castiel in the chest with it to no avail.

Trivia

 * Series creator Eric Kripke originally wanted the knife's origins to remain unknown to retain an air of mystery. When Sam asked where she got it, Ruby deflected the question with a joke. Alastair did not recognize it, remarking that it was a "magnificent piece" and telling Ruby "you must tell me where you found it." "As Time Goes By" finally revealed that it was forged long ago by the Kurdish people.

Appearances

 * Season Three
 * The Magnificent Seven (First Appearance)
 * Malleus Maleficarum
 * Jus In Bello
 * No Rest For The Wicked
 * Season Four
 * Lazarus Rising
 * It's The Great Pumpkin, Sam Winchester
 * I Know What You Did Last Summer
 * Heaven and Hell
 * On The Head of a Pin
 * The Rapture
 * Lucifer Rising
 * Season Five
 * Sympathy for the Devil
 * Good God, Y'all
 * I Believe The Children Are Our Future
 * Abandon All Hope...
 * Swap Meat
 * My Bloody Valentine
 * 99 Problems
 * The Devil You Know
 * Two Minutes to Midnight
 * Season Six
 * Caged Heat
 * The Man Who Would Be King
 * Let It Bleed
 * Season Seven
 * Season Seven, Time For a Wedding!
 * Repo Man
 * The Born-Again Identity
 * Reading is Fundamental
 * Season Eight
 * We Need To Talk About Kevin
 * What's Up, Tiger Mommy?
 * A Little Slice of Kevin
 * Torn and Frayed
 * As Time Goes By
 * Trial and Error
 * Goodbye Stranger
 * Taxi Driver
 * Clip Show