Play + free slot machines demo collection, categorizing them on our team readily in Australian Casinos Punters have certain expectations from any new. Harlequin being the missileboat sistership of the Mantis. Our. Harlequin-class Destroyer Missile-Boats in production for fire-support, newly upgraded with the substance known as Merculite, encased in missiles. . Production begins effective immediately. The mantis and Harlequin class destroyers.