Bio-plasma is a potent close-ranged Tyranid Biomorph -- often engineered by the Hive Mind into Tyranid Carnifexes -- that is capable of unleashing a potent short-ranged attack upon their foes. With this Biomorph, a Tyranid organism gains the ability to internally energise a form of organically-created plasma that can be vomited forth as a burning and blinding ball of incandescent green energy. Each ball of plasma has the equivalent force to a blast from an Imperial Plasma Cannon, but can only be hurled a short distance. Bio-plasma is formed from a highly corrosive exothermic chemical that releases massive amounts of heat once it is released from the Bio-plasma organ within the Tyranid bioform. Shortly before the plasma is launched, the bioform will usually let out loud screams as the projectile makes its way from its belly through the creature and out its gaping maw. This high-pitched scream is often the last thing the Carnifex's prey ever hears.
The most common Screamer-Killer strain of the Carnifex bioform is notable for its enhanced evolution of the Bio-plasma Biomorph. The Screamer-Killer's characteristic high-pitched screaming is caused by rasping plates in their oesophagus, which are used to energize Bio-plasma in their gut. However, instead of launching this plasma as a ball, the "vomit" acts as a deadly short range Flamer-like weapon. Screamer-Killers are also capable of using an electrical field around their claws to build up an incandescent Bio-plasma ball before launching it at a target over longer ranges.
Massive Bio-plasma-emitting spines can also be found on Tyranid bio-ships. These spines emit gargantuan balls of Bio-plasma that can devastate enemy voidcraft. Bio-plasma spines serve as effective short-range weapons batteries in void combat for Tyranid bio-ships.
- Codex: Tyranids (4th Edition), pg. 32
- Codex: Tyranids (5th Edition), pg. 46
- Deathwatch: Mark of the Xenos (RPG), pg. 31
- Battlefleet Gothic: Armada, pg. 84