The Tyranids have two special army-wide rules to ... it spawns a handful of Ripper Swarms that can immediately join the combat. You can never have enough Termagants, and the Tervigon is here ...

They often infest areas with a heavy Tyranid population ... but must be found in mission as a temporary heavy weapon. The Ripper Swarms will form swirling tornado-like masses that will charge ...