Amongst Migimúlli's pellets toward the back of the burrow is one completely compromised of polearm heads. They are all very old looking and rusted beyond use. Except for one, number forty in the image, which is still shiny and new looking. There is a pictogram of a fish embossed in the ferrule. If put upon a haft this becomes the blessed bident carried by the priests of Ula in ancient times. For stats see page 209 in the dmg. It has d3 daily charges of the spell dominate beast (phb 235) applying strictly to piscenes. It is also a +1 weapon applying to both to-hit and damage.