Serpents Spear

Requires attunement.
You can use your action to plunge the spear into
the ground, and choose a 10 foot square that you
can see within 60 feet. That area is then filled
with spears of cold water piercing up from the
ground. Each creature in the area must make a
DC 13 Dexterity saving throw, taking 4d6
piercing damage on a failed save, and half as
much damage on a successful one. The spear
cannot be used this way again until the next dawn.