The Mantys Engine is a VAN-Guard and can be used as a stealth weapon, when near enemy soldiers, stabs 2 of the spikes on its "arms" directly into his head, instantly killing the enemy. It is only in Killzone Mercenary and is sold in Blackjack's armory. Like most VAN-Guards, it costs 1250 Vektan dollars.
The Mantys Engine is a stealth drone which uses the two blades on its arms to instantly kill enemy soldiers. It is a great weapon to use when having trouble trying to get to your destination undetected, as it can float up to enemies on higher ground and kill them without making a noise. As it is a stealth weapon, it is easy to destroy when its under fire.