A Morgul-blade was a magical and poisonous dagger that was used by Ringwraiths in Middle-earth during the Third Age. After it tastes flesh, the dagger breaks, leaving a shard of the blade in its victim. The remaining blade soon turns to dust, and the shard works its way through the body to the heart. If the shard of the blade stays in the victim for too long the victim becomes a wraith.
As short daggers the Morgul-blades might not be very practical weapons to use in a battle so it might be reserved on Mordor´s greatest enemies or as a punishment.
A victim of this blade was Frodo who was stabbed by the Witch King himself. A fragment of the blade remained within the wound of Frodo, working its way toward his heart and threatening to turn Frodo into a wraith. Elrond was able to remove the shard and heal the wound, but each year on the anniversary of receiving the wound from the Morgul-blade Frodo became seriously ill. Only his eventual departure to Eldamar also known as the Undying Lands offered a permanent cure.
Athelas (or Kingsfoil) is known to slow the poisonous effect of the Morgul-blade, though true healing (usually Elven healing) is necessary in order to fully cure a victim. This remedy is also known to heal other Mordor-associated illnesses, like the Black Breath of the Ringwraiths.
Portrayal in adaptations
In the film The Hobbit: An Unexpected Journey (2012), a shade of the wraith uses a Morgul-blade to attack Radagast the Brown at Dol Guldur, but Radagast fends off the shade and takes the weapon, giving it to Gandalf. Gandalf later tries to use the Morgul-blade as proof that the White Council should attack Dol Guldur, but Saruman overrules him. Saruman believes that there is no proof that it could be a Morgul blade, but Galadriel points out that the blade was buried with the Witch-King of Angmar in a cave sealed by magic.
In EA's BFME2 Rise of the Witch-King, Captain Carthaen was stabbed with a Morgul-blade by Morgomir and became Karsh the Whisperer after the Dark Plague Ritual on the Barrow Downs; Carthaen became a wraith that journeyed across the Northern lands hunting for the enemies of the Witch King. His tortured spirit became free after Elrond of Rivendell killed him with his Noldorin sword. The spirit of Carthaen went to the Valar and Karsh's body was later destroyed (in the campaign).Template:Meweapons
In The Lord of the Rings Online , the Ranger Amdir was wounded by a Morgul-blade during the beginning of the Man and Hobbit Epic Quest lines. Even after Strider's atempt to cure him with Kingsfoil gathered by the player, Amdir left with Cargul during the Assault on Archet. His appearance changed when the player encountered him again in the Blackwold's Hideout, having a more undead or zombified face. Amdir ran away from the hideout, and was encountered again under Marshwater Fort. Later, now fully under the Enemy's control, Amdir, clad in red Nazgul robes, fought against the player one last time before finally being at peace.