The Klingon custom of holding open the eyes of a dying warrior and roaring skyward at the moment of death, warning the dead that a warrior is about to arrive.
When a Klingon warrior dies, those present hold the eyes open and then throw back their heads and howl. The cry is not mourning. It warns the dead that a warrior is on the way. The body is afterwards treated as an empty shell of no importance.
The ritual is introduced in Heart of Glory, in which Worf joins the renegades Korris and Konmel in howling over their dying comrade, to the astonishment of the Enterprise crew. Worf performs it again for K'Ehleyr in Reunion and for Jadzia Dax in Tears of the Prophets.
Discovery shows an older and more elaborate set of observances among the followers of T'Kuvma in The Vulcan Hello, who preserve their dead in coffins covering the hull of their ship.