no no no Blizzard copied the Tyranid. Tyranids were first described in Rick Priestley's Rogue Trader, the first edition of the Warhammer 40,000.At that time they were not an emphasised race in the game, instead representing a limited number of occasionally-encountered alien antagonists. Early Board Game Incarnations: Genestealers were introduced in the 1980s with Space Hulk, and later featured in Space Crusade, along with the short-lived Genestealer Magus. The first recognisable incarnation of Tyranid warriors appeared in Advanced Space Crusade in 1990, featuring biological weaponry such as boneswords and deathspitters.
Tyranids were first mentioned under the heading Tyranids and the Hive Fleets, and were illustrated in a form not too different from their latest incarnation.
The first Tyranids used conventional, non-biological equipment such as lasguns and flak armour (although the rulebook stated that these represented organic equipment with similar capabilities).The principal unit available to the Tyranids was the Zoat, a centaur-like creature enslaved to fight on the behalf of their Tyranid masters.
Second Edition:
Second Edition Warhammer 40,000, released in 1993, featured the Tyranids in the supplemental books Wargear and Codex Imperialis, and then later in their own devoted army Codex. An extensive model range was released, representing most of the units described in these publications. The army was, however, very different from the factions previously seen in the game. Notable were the huge numbers of rank-and-file units a Tyranid player was able to deploy compared to most other armies due to their low points cost (second only to the Imperial Guard, according to many players) and the large and flamboyantly designed centre-piece models, very different from anything Citadel had released before.
The tyranid player now had access to a range of unit types roughly equivalent to that of the other factions, including:Hive Tyrant, Termagants, Hormagaunts, the main adversary in Space Hulk Genestealers, Gargoyles previously seen in Epic 40,000, Tyranid Warriors, the Carnifex, Zoanthropes (a Tyranid psyker in addition to the Hive Tyrant), Lictors, and the Biovore.