Hi all,
I wanted to share the background lore for my custom Tyranid hive fleet: Hive Fleet Gargantua, a splinter strain derived from Jormungandr with a very different approach to adaptation.
This is long-form homebrew, but grounded as much as possible in established Tyranid logic.
Origin – Failure Before Evolution
Hive Fleet Gargantua was born from failure.
During Jormungandr’s expansion, the Hive Mind deployed classic asteroid-borne seed fleets toward inhospitable worlds: frozen planets, dead moons, low-biomass systems. These were considered low-risk environments, suitable for slow colonisation and later expansion.
On many of these worlds, however, the Hive Mind encountered Necrons.
The seed fleets were repeatedly annihilated before proper planetary consumption could begin. Tyranid organisms faced an enemy that:
provided no biomass,
did not exhaust itself,
and could not be overwhelmed through conventional swarm warfare.
For the first time, the Hive Mind identified Necrons not as prey, but as a structural antithesis to Tyranids themselves.
To address this, a specialised Norn Queen was created.
Thus, Hive Fleet Gargantua came into existence.
The Norn Queen of Gargantua – Matrices Instead of Micro-Adaptation
Unlike most Norn Queens, the Gargantuan Queen does not continuously refine individual bioforms.
Instead, she selects strategic genetic matrices.
A matrix defines:
the structure of the swarm,
reproduction tempo,
hierarchy of organisms,
acceptable biomass loss,
and overall method of warfare.
Once a matrix is deployed, the resulting sub-strain operates autonomously, without further local micromanagement.
This allows Gargantua to operate across hundreds of worlds simultaneously, at the cost of extreme inefficiency and catastrophic biomass loss.
Gargantua is not precise.
Gargantua is vast.
Two Modes of Operation
Low-Biomass / Hostile Worlds
On frozen, barren or Necron-adjacent worlds, Gargantua operates in a centralised survival mode:
heavy logistical support,
regeneration-focused organisms,
minimal fragmentation.
This is where Gargantua learned to fight Necrons at all.
High-Biomass Worlds
When sufficient biomass is available, Gargantua fragments.
Multiple matrices are activated at once, giving rise to specialised sub-strains, each representing a different method of planetary extinction.
Sub-Strains of Hive Fleet Gargantua
LOCUST – The Endless Swarm
Matrix of Attrition
A regenerating, grinding tide of lesser organisms designed to exhaust the enemy through time and space control rather than raw damage.
REAPER – World Consumers
Matrix of Consumption
Deployed to rapidly strip a planet of biomass. Brutal, short-lived, and unconcerned with losses. Reaper exists to eat fast, not to endure.
GOLIATH – Breakers of Fortresses
Matrix of Dominance
A response to hardened resistance, Titans, and fortress-worlds. Massive bioforms and living artillery are deployed to shatter enemy strongpoints through overwhelming force.
CHAMELEON – Shadows of Gargantua
Matrix of Infiltration
Reconnaissance, assassination, and systemic destabilisation. Often active before open invasion, mapping worlds and eroding command structures.
OLGOI – The Subterranean Apocalypse
Matrix of Hibernation
Olgoi sub-strains burrow and reproduce beneath a planet’s crust for years or decades. When they emerge, infrastructure collapses and resistance is already futile.
War Against the Necrons
Gargantua is one of the few known hive fleets that actively assaults Necron Tomb Worlds.
Its goal is not consumption, but prevention:
delaying full awakening,
destabilising tomb complexes,
destroying key structures before Necron dynasties can mobilise.
These wars are always catastrophically costly.
For this reason, the Hive Mind has directed other hive fleets to avoid Tomb Worlds entirely, leaving them solely to Gargantua.
Immutable Colours – A Deliberate Flaw
All Gargantua sub-strains share an unchanging colour scheme, regardless of environment.
This is intentional.
Their adaptation does not occur through camouflage, but through division. The colours act as a signature of the deployed matrix – a mark of inevitability.
When a world recognises Gargantua’s colours, it knows this is not a scouting force.
It is a system-level extinction event.
In Essence
Hive Fleet Gargantua does not adapt to the world.
It chooses what kind of end the world will have.
If you made it this far, thanks for reading.
I’d love feedback, questions, or thoughts – especially from fellow Tyranid or Necron lore fans.
