The Legarans were strictly adherent to protocol. Though nondescript physically, they preferred to live in a pool of thick swirling ooze, which was carefully maintained at a constant 150 °C. The Legarans preferred no furniture, no (wall) decoration, and little lighting.
In 2273, Vulcan Ambassador Sarek began communicating with the Legarans in order to form relations with the United Federation of Planets. It was a mission that lasted 93 years until they agreed to first contact, in 2366, called the Legaran Conference. It was successful, and a treaty was established. (TNG: "Sarek")