Matalolok

Matalotok is frigid to the touch and wreathed in mist.
+3 to Attack/Damage roles. Versatile 1d8/1d10
Requires attunement. If its owner is deceased or
no longer on the plane, attunement is
instantaneous to the next wielder.
You are immune to cold damage while holding
Matalotok. Whenever it deals damage to a creature,
the hammer radiates a burst of intense cold in a
30-foot-radius sphere. Each creature in that area
takes 10 (3d6) cold damage.