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 emphasized race in the game, instead representing a limited number of occasionally-encountered alien antagonists. In later editions the Tyranids became a major race, popularized by a number of successful board games. Unlike most Warhammer 40,000 races, the Tyranids do not have a Warhammer Fantasy Battle counterpart.
Tyranids are typically a fast, close-combat army that rely on overwhelming their enemies through superior numbers. They may also be bio-morphed to rely heavily on ranged combat, or field an impressive but small array of monstrous titans rather than a typical swarm. Tyranid armies are therefore able to bring a varied threat to bear on their opponents.
The hive fleets so far introduced by Games Workshop include Hive Fleet Behemoth, Hive Fleet Kraken, and Hive Fleet Leviathan. It is noted that these names are those ascribed to the Tyranid incursions by the scholars of the Imperium, rather than the Tyranid civilization themselves. There is no evidence shown in the fiction that Tyranids have language or civilization as understood by the protagonist civilizations native to the Milky Way. In many stories they communicate with a complex array of insectile clicking and buzzing noises, as well as reptilian war cries, growls and hisses. Although this may be a theory or thought, Tyranids communicate via a strong synaptic link to the hive mind. The synaptic conductors use the link to press onwards the tyranids, communicating with them using telepathic abilities.
There have been three major hive fleets to date, Hive Fleet Kraken, Hive Fleet Leviathan and Hive Fleet Behemoth. There are many other Tyranid hive fleets that have been destroyed or are still emerging, such as Hive Fleet Jormungand, Colossus, Tiamet, Scarabus, Ouroboris, Reatherus and many more.
Genestealers were introduced in the 1980s with Space Hulk, and later featured in Space Crusade, along with the short-lived Genestealer Magus. The first recognizable 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 in Warhammer 40,000: Rogue Trader, and were illustrated in a form not too different from that of Gaunts.
The first Tyranids used conventional, non-biological equipment such as lasguns and flak armor (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.
Next week we will look at the Tyranids codex released for 2nd edition and onward to 5th edition.