The feathered and masked costume that Dennett collected represented ‘the king’s policeman’. A frightening presence, the spirit of ndungu had the authority to identify and punish people who had broken the rules of Kongo society.
“No one is supposed to know who he is, but got-up in a hideous double-faced mask, and dress made entirely of dried leaves of the banana or plantain-tree, very bushy and heavy-looking, he occasionally comes among the people armed with a long wooden sword. Everything he touches on his way becomes his property, thus you can imagine the disturbance his visit creates: all is confusion and hurry, as the native vainly attempt to hide their little before his coming.
He is supposed to watch over their morals and punish and offender by crucifixion. Generally he appears on the scene after some irregularity in the fall of rain occurs, as the Nkissist in Cabenda believes that the committal of certain indecencies is punished by the non-appearance of rain in its proper season.”
Taken from Richard E. Dennett, Seven Years Among the Fjort, 1887.