Matalotok

The Frost Father: Lord Kostchtchie's hammer, which Zariel stole. We freed the demon lord without it.

[!example]- Mechanics (Descent into Avernus)
Weapon (warhammer), legendary (requires attunement). While holding it you are immune to cold damage. Whenever it deals damage to a creature, it releases a burst of cold in a 30-ft-radius sphere: each creature in the area takes 10 (3d6) cold damage. Made by Thrym, god of frost giants. Source: Descent into Avernus, appendix C.

#item #artifact