Tervigon
Games Workshop has never really been known for gender equality amongst its armies to a degree **. Apparently someone told GW this, and the response was to give the Tyranids their own guaranteed female unit who happens to have been evolved from the Carnifex Genus: The Tervigon.
- The Eldar are co-ed, especially the Harlies and Dark Eldar, but the Craftworlders and Corsairs are a bit less inclusive. The Necrons are technically co-ed though they're now genderless robots with no visual indication of their former gender, with male rulers being called Phaerons and female rulers being Phaerakhs. Orks are asexual semi-fungus symbioses but look masculine. Tau are equal opportunity, though the genders are visually similar and fully armored they're indistinguishable. The only major inequality is in the Impreium, with the only playable ladies being the Bolter Bitches. Having said that, the lore features many more prominent males than females.
A Tervigon is very similar to a Tyrannofex although a Tervigon is arguably more suited to Close Combat, and instead of having a bio-weapon has spread legs and a uterus that could rival octo-mom literally filled with as many egg sacs as your opponents have bullets. In combat, she births entire broods of Gaunts, allowing you to overwhelm enemy groups with sheer numbers, since she puts out 3d6 Termagaunts a turn - and can do this every shooting phase. If you rolled doubles, she couldn't produce more gaunts for the rest of the game , but otherwise, the skies are the limit. Though she's not quite as directly useful as other heavies, the simple fact that she's essentially the Commander Kubrik Chenkov of the Tyranids means she's a massive source of tarpitting. She's also good in close-combat, being a monstrous creature and all, but there are other Tyranid organisms that do it better.
The Tervigon's constant Gaunt production has resulted in many hilarious discussions on /tg/. Many 'Nid-playing fa/tg/uys asked how her ovaries came to be fertilized and are ready to spew forth meat shields for the hive mind. Some think she is akin to an aphid, being born pregnant (the anti-lulz strictly-canon brigade leans toward this, since Tervigons act as anti-boarding parties during FTL flights); other wilder claims support her in a relationship with the local Hive Tyrant (or Tybalt as he prefers to be called); others say she is a whore hiring herself out to Trygon, Mawlocs, and when she's desperate, Haruspexes and Maleceptors. The most common claim is that she is also a he (see Slaanesh).
Fittingly enough, in 7th ed. we're running into skub-tastic flame wars about whether 'gaunts spawned from battle-forged Tervigons get any of the formation bonuses (namely Objective Secured), which is kind of relevant because Gaunts are also scoring units. Since the rulebook doesn't say the spawned 'gaunts do get them, most people just say "no" out of simplicity.