Dungeon Treasures (Rev. 4)

As of build 10.0.0, certain dungeon bosses are able to drop pieces of sets of treasures unique to the dungeon. The individual treasures and complete sets currently have one use; feeding pets. But this is not a recommended reason to buy them, since it probably isn't the main reason for them.
NOTE: Some treasures say "double-click to equip" when you hover over them. Whether this is a signal that treasures could later be used as equipment or if it was just an error in coding is not known.