Waterdrop Pendant

This Pendant is a token from the Ottersfolk from Lady Lutrina, and given by Sir Tonq to Reylynn.
As a bonus action, the pendant allows the wearer to encase themselves in a block of solid ice for 1 minute.
While encased, the wearer cannot take actions or cast spells, and cannot be the target of any attacks or spell effects.
The ice block is immune to Piercing, Slashing, and Bludgeoning damage but can be damaged when exposed to high temperatures.
Once used, the pendant cannot be used again until after a long rest.
Additionally, if the wearer is reduced to 0 hit points while the pendant still has its charge, they are instead reduced to 1 hit point and encased in a block of ice for 1 minute.

We got this item after saving The Dome in session 23 - Heavens' Outcasts.