E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A bogie or bugbear in the Mandingo towns of Africa. As the
Kaffirs have many wives, it not unfrequently happens that the
house becomes quite unbearable. In such a case, either the
husband or an agent dresses himself in disguise, and at dusk
approaches the unruly house with a following, and makes the most
hideous noises possible. When the women have been sufficiently
scared, Mumbo seizes the chief offender, ties her to a tree, and
scourges her with Mumbos rod, amidst the derision of all
present. Mumbo is not an idol, any more than the American Lynch,
but one disguised to punish unruly wives. (See Mungo Park:
Travels in the Interior of Africa.)