Magic Items

Weapon (rapier), very rare (requires attunement)
When you hit with an attack using this magic sword, the target takes an extra 1d6 cold damage. In addition, while you hold the sword, you have resistance to fire damage.
In freezing temperatures, the blade sheds bright light in a 10-foot radius and dim light for an additional 10 feet.
When you draw this weapon, you can extinguish all nonmagical flames within 30 feet of you. This property can be used no more than once per hour. This extraordinary weapon is crafted from a single piece of ice with a pommel wrapped in braided leaves. If wielded in temperatures in excess of 90 degrees, rivulets of water run down its blade—soaking the hand holding it. Despite this, it never melts away. This item can be found in the Dungeon Master’s Guide.

Wondrous Item, very rare
You can speak the carpet’s command word as an action to make the carpet hover and fly. It moves according to your spoke directions, provided that you are within 30 feet of it.
The natural fibers of this 5-foot by 7-foot rug have been dyed with patterns of overlapping blue and red feathers.
Size: 5 ft. x 7 ft. Capacity: 600 lb Flying Speed: 40 feet

Weapon (longbow), very rare (requires attunement)
When you nock an arrow on this bow, it whispers in Elvish, "Swift defeat to my enemies." When you use this weapon to make a ranged attack, you can, as a command phrase, say, "Swift death to you who have wronged me." The target of your attack becomes your sworn enemy until it dies or until dawn seven days later. You can have only one such sworn enemy at a time. When your sworn enemy dies, you can choose a new one after the next dawn.
When you make a ranged attack roll with this weapon against your sworn enemy, you have advantage on the roll. In addition, your target gains no benefit from cover, other than total cover, and you suffer no disadvantage due to long range. If the attack hits, your sworn enemy takes an extra 3d6 piercing damage.
While your sworn enemy lives, you have disadvantage on attack rolls with all other weapons.

This elven bow has the soul of a Thayan rebel permanently

Weapon (warhammer), legendary (requires attunement)
Matalotok, the Frost Father, is an ancient hammer fashioned by Thrym, the god of frost giants. The favored weapon of the demon lord Kostchtchie, Matalotok is frigid to the touch and wreathed in mist.
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.

You gain one 9th-level spell slot, provided that you already have one.

This black studded leather armor is made from the hide of a Far Realm monstrosity. This hide’s exposure to the Far Realm protects its bearer from extreme temperatures. If the armor is flipped inside out, a game of tic-tac-toe using the letters “M” and “E” is visible.