What is the name of Cú Chulainn's barbed spear?

The name of Cú Chulainn’s barbed spear is Gáe Bulg. It is the fearsome weapon associated with the Ulster Cycle’s greatest warrior-hero.

According to the Táin Bó Cúailnge, the warrior woman Scáthach trained Cú Chulainn in Alba and taught him the special technique for using the spear. She trained Ferdiad as well, but reserved this deadly feat for Cú Chulainn.

The weapon’s most famous use comes during Cú Chulainn’s duel with Ferdiad. Sent through the water by Cú Chulainn’s charioteer Láeg, it pierced Ferdiad’s armor and spread barbs through his body. Some versions describe seven heads, each with seven barbs. It was also used in the killing of Cú Chulainn’s son, Connla.

The name is often translated as “belly spear,” “gapped spear,” or “spear of mortal pain.” It is not the same weapon as Caladbolg, a sword associated with Fergus mac Róich and later linked linguistically with Arthurian traditions.