Embellished with cowrie shells, beads, seed pods, copper sheeting, goatskin, and hair, bwoom is one of three types of royal Kuba masks, all of which are treated as embodiments of nature spirits (mingesh). According to one local interpretation, the bwoom mask represents a prince who suffered from a neurological condition that caused his head to swell with accumulated fluid. Another says that bwoom is the image of one of the original Twa (Pygmy) inhabitants of the region. During performances the masks reenact episodes in the foundation of the kingdom.