Source: Storm King's Thunder

Weapon (greataxe), legendary (requires attunement)

In the Year of the Icy Axe (123 DR), the frost giant lord Gurt fell to Uthgar Gardolfsson-leader of the folk who would become the Uthgardt barbarians-in a battle that marked the ascendance of humankind over the giants in the Dessarin Valley. Gurt's Greataxe was buried in Morgur's Mound until it was unearthed and brought back to Waterdeep. After laying in the city's vaults for decades, the axe was given to Harshnag, a frost giant adventurer, in recognition of his service to Waterdeep. Uthgardt barbarians recognize the weapon on sight and attack any giant that wields it.

You gain a +1 bonus to attack and damage rolls made with this magic weapon. It is sized for a giant, weighs 325 pounds, and deals 3d12 slashing damage on a hit, plus an extra 2d12 slashing damage if the target is human.

The axe sheds light as a torch when the temperature around it drops below 0 degrees Fahrenheit. The light can't be shut off in these conditions.

As an action, you can cast a version of the Heat Metal spell (save DC 13) that deals cold damage instead of fire damage. Once this power is used, it can't be used again until the next dawn.