Starcraft 2 Hydralisk strategies may vary from player to player, as this unit is a rather versatile one. The Zerg Hydralisk is a franchise staple and is often referred to as "Hydra" by the online community. The Hydralisk was a very po[censored] r unit among Zerg players during the Brood War, and Starcraft 1 eras.
In large numbers this creature is an unit that can cause a lot of damage. They do not have the hit-points of a Roach, however, or the attack power and are more expensive, but, they are one of the few units that can fire upon both ground and air units. With adequate upgrades a large number of Hydralisks could be used in almost any cir[censored] stance with proper support and creep spread. This unit is also capable of burrowing but cannot move whilst burrowed, however.
These units can be purchased in the mid game, but they do require a large amount of minerals to produce in the mid game and they also require gas. The fact that they are so expensive in the mid game is reason enough for most players to invest in them later on, around the late game. However, throwing a "Hydra" or two, into a Zerg force never hurts. It isn't expected that you should face any flying units until later on in the game, unless your opponent really pushes towards building quick air units, so building a large amount of Hydralisks early on isn't always necessary.
Hydralisks, like most Zerg units, are best used in large groups with other supporting units and their intrinsic versatility due to their ability to target most target types, makes them great for swarms. They are a very po[censored] r unit for this tactic traditionally. In Starcraft 1 they were used excessively by players, as they were cheaper than Goliaths, or Dragoons and you could spawn more of them.
Starcraft 2 throws a few wrenches into the mix, however, so it isn't wise to solely rely on a single unit type, however if the situation were to arise in which you are in combat with a full group of these unit types, a group of Hydralisks could certainly inflict heavy damage against most adversaries. There is also an upgrade called Grooved Spines which will increase their attack range by one.
The key to success at Starcraft 2, however, is to be able to read your opponent and have the means to confront any strategy that may be thrown at you adequately. Mixing it up is certainly key, know your opponent and know their weaknesses. On that note these units are great at countering most any early game air units in large numbers with supporting units. They are a Zerg player's quintessential ground support as Roach, Ultralisk, and Zergling units are incapable of combating flying units.
By mid-game the production of these units is recommended, especially if you are using a tactical approach that involves the use of ground units. If you have adequate flying units, however, you could avoid using the Hydralisk entirely.
This creature is a very po[censored] r one and has had a cameo in Warcraft 3, another game produced by the Blizzard corporation. These iconic alien monsters can be found in art work pertaining to the game, artwork that spans instruction manuals, to official and unofficial websites. Artistic renditions of these creatures are not necessarily restricted to the domain of Blizzard's property rights, images of these creatures have entered into the world at large, and can be found throughout the gaming community. They are rather emblematic video game characters.