The mantis and Harlequin class destroyers. Harlequin-class Destroyer Missile-Boats in production for fire-support, newly upgraded with the substance known as Merculite, encased in missiles. 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. Production begins effective immediately.