In variants that have multiple Norse-based non-quest-artifacts, valkyries recieve a randomly chosen one of them as their first sacrifice gift.

New artifact Gungnir, an unaligned spear (spear of Odin from Norse mythology). Confers nothing, but has +20 to hit (or whatever is necessary to make a hit basically guaranteed) and +d8 damage.

Note that SpliceHack implements Gungnir, but not as described here.