This strategy is based on morphing lots of Hydralisks while upgrading their carapce and acid capacity at the same time, developing overlord abilities like speed and dropability.As you will estimate, this tactic needs high amount of vespene, especially relative to the conventional tactics.You can start this tactic by two ways;The first one is a defensive type which is based on accumulating more and more hydralisks and drop them to the weak and most difficult place for enemy with high numbers.Here you must not forget lurkers and zerglings which strengthen the assault while expanding the attack spectrum of your army.But here in defensive type, you cease from making pressure at your enemy which will be dangerous but or may be more easy according to your rival’s attack profile.If you choose the second one ,or we can say offensive type the pressure at the enemy will rise automatically because at the very early stages of the game, you will start attacking by just morphed and little amount of hydras and you will continue your strike.But if you do not set the balance of the pressure, you will take more harm than advantage.So here you must optimise your strategy and you must know your enemy profile.This tactic is weak against macro based Terrans, because of Tank’s splash and high rated attack capacity.But it is useful against Zerg or Protoss.Also the efficient usage of this tactic is at 2v2 or 3v3 games where the focus at players are divided ,gives you an extra chance to strike surprisingly.