Charpactin

The Charpactin are a xenos species of sentient fungoid creatures who communicate entirely in bursts of ultraviolet colour.

These strobing emanations prove surprisingly effective at subduing and transfixing living beings, rendering them docile and amenable.

When Water Caste diplomats from the Fifth Sphere Expansion sept of Fe'saan encountered them, the T'au quickly negotiated a client-state treaty, drafting many of these creatures into their growing Edification Corps.