The trope has the wolf, the raven, and the eagle follow warriors into battle to feast on the bodies of the slain.
The term originates with Francis Peabody Magoun, who first used it in 1955, although the combination of the three animals was first considered a theme by Maurice Bowra, in 1952.
[2] The beasts of battle presumably date from an earlier, Germanic tradition; the animals are well known for eating carrion.
John D. Niles points out that they possibly originate in the wolf and the raven as animals sacred to Wōden; their role as eaters of the fallen victims certainly, he says, accords with the fondness of Old English poets for litotes, or deliberate understatement, giving "ironic expression to the horror of warfare as seen from the side of the losers.
"[4] While the beasts have no connection to pagan mythology and theology in the Old English poems they inhabit, such a connection returns, oddly enough, in Christian hagiography: in Ælfric of Eynsham's Passio Saneti Edmundi Regis (11th century) a wolf guards the head of Saint Edmund the Martyr, and in John Lydgate's The Life of Saint Alban and Saint Amphibal (15th century), "the wolf and also the eagle, upon the explicit command of Christ, protect the bodies of the martyrs from all the other carrion beasts.