The Garan were a Delta Quadrant species. Their necks contained glandular tissue in which growth hormone was found.
A Garan mining colony was located near Tak Tak space. In 2373, the USS Voyager received a distress call from the colony, requesting medical assistance. It was discovered that the colony had been infected by a macrovirus. The Tak Tak destroyed the colony to prevent the spread of the virus, but it had already been transferred to Voyager. (VOY: "Macrocosm")
The civilian trader Onquanii was also a Garan native. (VOY: "Warhead")
Onquanii's race was never identified on screen, but since he appeared identical to other Garans, it is likely that he was also of that race.