This page contains information regarding Star Trek: Discovery, and thus may contain spoilers.
The Saurians resembled humanoid lizards with scaly skin that could be pink or gray. Their large black or yellow eyes were endowed with both vertical and horizontal eyelids, and granted them an enormous visual spectrum of 74,000 nanometers. (Star Trek: The Motion Picture; DIS: "Brother", "Far From Home")
They had six nasal canals, making certain afflictions such as the common cold particularly miserable. (DIS: "An Obol for Charon") Saurians shed their skin once a year, during which time they were forced to avoid any areas where hygiene was important such as mess halls. (DIS: "The Sanctuary")
Saurian brandy was an alcoholic beverage, bottled since at least the 22nd century, that had been popular in the Federation for centuries. (TOS: "Requiem for Methuselah", "The Enemy Within"; DS9: "Behind the Lines") It was illegal in the alternate reality as of 2263. (Star Trek Beyond)
The original Saurians were designed by Fred Phillips and Robert Fletcher for The Motion Picture. With the approval of Gene Roddenberry, the Saurians, as well as numerous other new species in the film, were named by Fletcher and provided a backstory by him. The following is a brief description, in Fletcher's own words:
"SAURIAN – A lizard person, very able, excellent space officers. Learned to communicate in Earth tongue, have complicated vocal language of own. Have upright, direct posture. Intelligent. Can breathe a number of gases. Valuable in exploration of new areas because of enormous strength due to four hearts. (Note: in rec deck scene only.)" (The Making of Star Trek: The Motion Picture, pp. 132-133; Starlog #33, April 1980, p. 71; Star Trek: The Magazine Volume 2, Issue 9, January 2002)
Star Trek: Star Charts ('United Federation of Planets I") and Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385") depicted a planet called Sauria in the Alpha Quadrant star system Sauria (Psi Serpentis). This was a trinary system consisting of three G-class stars. Sauria was listed as a Federation member as of 2378.