Tyranids: Neurogaunts

Neurogaunts are specialized Tyranid bioforms that function as essential relays for the Hive Mind's synaptic network. Unlike typical combat-focused gaunts, these eyeless, scuttling creatures are driven by parasitic neurocytes attached to their backs, which allow them to project command signals and extend the range of nearby Synapse creatures.

Core Characteristics & Lore
Synaptic Relays: Their primary purpose is to act as living conduits, extending the "Shadow in the Warp" and ensuring larger Tyranid beasts maintain control over the wider swarm.
Bodyguards: They often swarm around key synaptic nodes, such as the Neurotyrant, serving as a sacrificial shield to protect these vital command units.
Physical Traits: They are small, nimble, and eyeless, scuttling with "mindless vigour" and attacking with needle-sharp claws and teeth when forced into combat. 
Tabletop Gameplay (10th Edition)
Unit Composition: A standard unit consists of 11 models: 10 small Neurogaunts and one larger Nodebeast, which features a more prominent dorsal growth.
Utility: They are one of the cheapest Tyranid units, often used as "cannon fodder" or "action monkeys" to hold backfield objectives and screen more expensive units.
Key Ability (Neurosytes): This ability allows them to spread the Synapse keyword to other Tyranid units while they themselves are within range of a Synapse creature, effectively widening the army's control zone.
Stat Line: They have poor defensive stats, typically featuring Toughness 3, a 6+ Save, and 1 Wound per model.