Galg
The Galg (Adumminus sextus) are a race of weird cephalopods from the planet of Adummin. They are a race whose individuals which resemble a mass of tentacles with a bulbous head. They are also described as having six tentacle limbs instead of arms or legs and no head, but clusters of eye-like organs that "wave like grass in a breeze".
Young Galgs produce an oily secretion that is drunk by the Dark Eldar, giving an invigorating effect and occasional hallucinations.
When fighting in close quarters, Galgs have been known to latch onto an enemy's back and wrap their tentacles around the opponent's throat.
Unfortunately, due to bureaucratic fuck-up, the Galg were actually mischaracterized as a bunch of broad, barrel-chested frog-like humanoids in Warhammer 40,000. Having wide toothy mouths, and bulbous black eyes whilst producing psychotropic poison on their skin, much like some real-world toads. Liber Xenologis seem to have cleared up the misunderstanding as the initial description seem to depict a completely separate Xenos race instead.
The Galg are also a mercenary race, selling their services to the highest bidder, oftentimes finding themselves in the employ of the Tau.