Craftable. Can be worked into an ordinary piercing weapon to add an additional 1d6 fire damage on hit.
Remorhaz Fang Weapon
Crafted from: Remorhaz Fang, 150 gp of materials and time.
A piercing weapon that deals an additional 1d6 fire damage on hit, once per day. Takes a tenday to craft on your own, but a talented blacksmith or Reghed craftsman could work the job faster. Perhaps a smith could even eke out more uses of the fang.
A dagger that adds an additional 1d4 psychic damage on hit.
Vial of Sea Hag blood
Craftable. Four hours of distillation into a tincture produces a Potion of Horrific Appearance.
Potion of Horrific Appearance
Crafted from: A Vial of Sea Hag blood
When poured over a humanoid that is of size medium or smaller, a magical illusion washes over them, making them look like an ugly creature of vaguely humanoid proportions. This illusion lasts for one hour. A creature can use an action to visually inspect the illusion and succeed on a DC 16 Intelligence (Investigation) check to discern that the humanoid is disguised.
Frost Giant's Greataxe
Deals 3d12 slashing damage on hit. Looks cool as hell.
Hugely Heavy. The wielder must be size Medium or larger to hold the giant greataxe. Creatures size Medium or Large roll with disadvantage. If the wielder's Strength score is less than 20, attacker must pass a DC 14 Strength saving throw or have their movement reduced to zero and fall prone.
Proficiency with a greataxe allows you to add your proficiency bonus to the attack roll for any attack you make with it.