|Mass Effect 3|
The Yahg are a race of massive apex predators from the world of Parnack whose rise to sentience in no way blunted their violent nature. A group of yahg is unable to cooperate until a single leader has been determined through either social maneuvering or brute force, but no grudges are held once a yahg established dominance. Former rivals serve their new superior's purposes with unflinching loyalty and relentless determination, a legacy of their origin as pack species.
Their eight eyes are another sign of their hunter ancestry--all four pairs are geared towards tracking down and predicting the movements of prey. Sophisticated and keenly developed sensitivity to movement and light have made yahg masters at reading body language, regardless of species. Much to their short-lived chagrin, the Council's first contact teams discovered it was nearly impossible to lie to the yahg.
The yahg had technology equivalent to 20th century Earth standards when they were discovered by the Council in 2125. The Council's ambassadors approached the yahg as friends and allies instead of subordinates, a baffling sign of contempt from newcomers on Parnack. The yahg attacked when it became apparent that the alien diplomats stubbornly considered themselves sovereign people instead of new underlings. Parnack remains off-limits by order of the Council, which fears that the yahg's size, aggression, and obsession with control make them poorly suited for integration into the galactic community.