This ivory scepter is carved from the fang of the ancient sea serpent Andratharygoth into the visage of a sea serpent, it's winding coils twisting around the central body with a pair of small flecks of blue crystal set into the eyes that glow with a cool light.

You can use this rod as a spellcasting focus. While holding this rod, you gain a +2 bonus to spell attack rolls and the saving throw DCs of your spells.

Cold Focus. While attuned to this rod you gain resistance to cold damage. 

Frigid Depths. Whenever you cast a spell that deals cold damage, you can use the rod to deal the maximum damage instead of rolling. Once this property is used, it can’t be used again until the next dawn.