: Mammatus eventually agrees to let the Ninja take the amulet for safekeeping. However, upon inspection, Zane reveals that the amulet they have been given is a fake .

: After navigating the dangerous Storm Belt in the Hydro Bounty , the Ninja reach the island and warn the Keepers' leader, Mammatus, of Kalmaar's impending invasion.

: The Chief of the Keepers who initially distrusts the Ninja but eventually tries to help.