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".
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.