During male initiation ceremonies (nkaan), a helmet mask called bwoom is danced; the performance is used to teach initiates about Kuba history, cultural values and to instil an appreciation for Woot (the founding father and ancestor of all Kuba kings).
There are differences in opinion about what bwoom represents; some sources point to the mask representing a commoner, while others point to it being a representation of a prince (the king's younger brother) or of a pygmy. Sources that point to it representing a pygmy believe that bwoom was created for the reigning king at the time, Miko mi-Mbul. A pygmy created the mask as an alternative to the royal mask mwaash ambooy, to be worn by the king to cure his mental illness (hence its local description 'a person of low standing scarcely worthy of being embodied by the king'). However bwoom is universally believed to be a nature spirit (ngesh; pl. mingesh) seen by nkaan initiates and used to reflect the influence of nature spirits on Kuba life.