HURRIANS

Planet of Origin: Hurria

The Hurrians are a sentient species which had developed a non-competitive interstellar empire as of the late 19th century. 

They generally look like an Earth's monkeys, with long thin arms and stubby tails, standing about a meter tall, with black skin covered in dense fur, and a mobile nose on their faces. They evolved from small primates, rather than apes, are vegetarian and mostly non-competitive. They abhor the idea of violence and war, and have accepted as fact that all other species end up destroying their own civilizations after discovering nuclear power. Thus, rather  trying to interfere in their warfare or prevent them. they developed a policy of monitoring other civilizations from distance, waiting  to come down and help the survivors build a new civilization, genetically altering them to remove their competitive impulses and making them subjects to the Hurrian empire.

Although they describe these actions as righteous and helpful, the Hurrians benefit of the removal of competition which ensures their status as the dominant power of the galaxy and make each species pay for the help received in one form or another.  They are known to have aided the Mauvs in such a manner. 

Source:  Isaac Asimov, The Gentle Vultures(1957)