Brooding Darkwater Clam

Brooding Darkwater Clam drops from Northrend murlocs.

A similar item exists, Darkwater Clam, which is dropped by the same mobs.

This item was likely related to a blizzard post parodying the outcry against various game changes—in this case, the change that allowed clams to stack:

There are reports that this item can be obtained by fishing, but reports indicate it is only rarely encountered.