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