Tyrannocyte

It moves, it shoots!, but wait!! For it can transport!! Everything people liked about the Mycetic Spore packed into it and with awesome additions.

The Tyrannocyte is a unit that fulfills the exact same purpose a mycetic spore but coming WITH a model this time, released not long after the Maleceptor and Toxicrene kit and their accompanying White Dwarf rules. Even better than that, it's a drop pod that can MOVE (though rather slowly) and can fire FIVE Deathspitters (or Barbed Stranglers or Venom Cannons) at any nearby targets as long as they're within range/LOS. It's also improved by making it even more accessible, as now instead of only being a transport for certain models, it's now open to everything, limiting only to units of 20 models or one Monstrous Creature.

Course, though this sounds like every Nid Player's wet dream, the bigger score comes from the other models the kit can make: A spore mine that can hit flyers AND a living fortification that can fire five guns and a bunch of other fun rules to make area denial a thing without needing Gaunts everywhere.

As for the Tyrannocyte's fluff, well it's basically a Mycetic Spore now that Mycetic Spores have been given the unperson treatment. After landing and disgorging its passengers it unravels a second, hidden flap of skin and fills it with helium-producing bacteria or whatever, and that's how it's able to move around. Occasionally the Hive Ships will fill it with Spore Mines instead and drop it as a special fortification/synapse signal booster.

Tyrannic Bio-Organisms
Leader Organisms: Broodlord - Hive Tyrant - Swarmlord - Tyranid Warrior
Small Creatures: Gargoyle - Genestealer - Hormagaunt - Ripper - Termagaunt
Medium Size
Creatures:
Biovore - Hive Guard - Lictor - Neurothrope - Pyrovore
Ravener - Tyrant Guard - Venomthrope - Zoanthrope
Monstrous Creatures: Carnifex - Dimachaeron - Exocrine - Haruspex - Malanthrope
Maleceptor - Mawloc - Tervigon - Toxicrene - Trygon - Tyrannofex
Gargantuan Creatures: Cerebore - Dactylis - Hierodule - Malefactor - Nautiloid - Viragon
Flying Creatures: Harpy - Harridan - Hive Crone
Bio-Titans: Dominatrix - Hierophant - Hydraphant - Viciator
Other Organisms: Bio-Weapons - Cortex Leech - Mieotic Spore - Mucolid Spore
Mycetic Spore - Spore Mine - Sporocyst - Tyrannocyte - Zoats
Auxiliaries: Genestealer Cult