A metal ritual bowl used by the Frogkin and Ratfolk for the worship of Buurglap, the Frogkin god of war.

It vibrates wondrously, making a hauntingly beautiful sound that modulates with the motion of the rippling water. - Tome of Encounters (RPA-ADV6)

The basin has a calming effect on the area around it, and a purifying effect on the liquid it holds:

A sense of great peace flows through you and the tone of the bowl hums quietly for several moments. You wish it would never end. When it finally fades completely, you notice the buzz of insects has ceased. It’s as if all of nature were listening to the sound. The swamp water in the bowl, once murky and foul, is now crystal clear and sweet smelling. - Tome of Encounters (RPA-ADV6)

You catch a Ratfolk woman carrying the basin in Bogroot Swamp, and soon find yourself surrounded by her pack:

• Side with the Ratfolk and the Demon Elsifor, and participate in their ceremony:
  • Find peace, and be rejuvenated.
  • Struggle to calm your mind, and be recovered to a lesser degree.
• Side with the Frogkin and fend off the ambushers:
  • Succeed, and scare them away, leaving the bowl with you.
  • Fail, and they sail away.