Olosa (oni-osa , owner of the Lagoon) is the goddess of the Lagos Lagoon, and the principal wife of her brother Olokun, the sea-god. Like her husband she is long-haired. She sprang from the body of Yemoja.
Olosa supplies her votaries with fish, and there are several temples dedicated to her along the shores of the lagoon, where offerings of fowls and sheep are made to her to render her propitious. When the Lagoon is swollen by rain and overflows its banks she is angry, and if the inundation be serious a human victim is offered to her-, to induce her to return within her proper limits.
Crocodiles ate Olosa's messengers, and may not be molested. They are supposed to bear to the goddess the offerings which the faithful deposit on the shores of the Lagoon or throw into the sedge. Some crocodiles, selected by the priests on account of certain marks borne by them, are treated with great veneration; and have rude sheds, thatched with palm leaves, erected for their accommodation near the water's edge. Food is regularly supplied to these reptiles every fifth day, or festival, and many of them become sufficiently tame to come for the offering as soon as they see or hear the worshippers gathering on the bank.