Volgs were a species of herding animals native to the planet Varala.
Laas once assumed the shape of a volg and migrated with a herd of the animals to the southern continent of Varala.
By the time the herd returned to their breeding grounds the following summer, they'd been fenced off by the Varalans. After that, the herd died out within two generations. (DS9: "Chimera")