The main boss of the Metal Slug Defense stages, Jupiter King, has huge health, high range and high damage, but is pretty slow when it comes to attacking, which results in him working a lot like Dark Emperor Nyandam. Since his DPS turns out to be quite low, this enemy won't be difficult to defeat once his support is taken care of. What lets him stand out is the ability to knock back cats, but he won't do that often, since he attacks every 13 seconds, so treat this as a minor annoyance.