I found a Hydralisk hidden in one of the Warcraft 3 campaign maps and it helped Tyrande survive against an army of Doomguards, thus they're important to Warcraft's lore.
Where the hell is my Zerg expansion Blizzard? I want my Hydralisk, it proved to be an invaluable ally and changed Warcraft forever. Without that Hydra Tyrande would be dead.
WTF Blizzard? Millions of players have asked for this.