One of the races, now extinct, in Larry Niven
's Known Space
books. They lived a few billion years ago. You can get a good history of them from World of Ptavvs
. The Thrint, though not particularly smart, have something they call the Power, which is a type of telepathy which allows them to control any creature with a notochord
. This allows them to enslave other races, and if those races have high technology, such as the Tnuctipun
, they can use them to access that technology. The Thrint thereby ruled the entire galaxy.
They had to give the Tnuctip more freedom so they could come up with inventions, the Tnuctip used this freedom to plan a revolution. Seeing that they could not win the subsequent war, the Thrint had a giant Power amplifier built and ordered all beings in the galaxy to commit suicide. They seeded planets with food yeast for Bandersnatch, and current sapients in Known Space (including humans) evolved from them.