Large, hairy quadruped with a long neck, larger than a horse with an extremely keen sense of smell, native to the planet Abydos. Though the origins of the mastadge are unclear, these creatures may be related to Terrman horses who adapted in the harsh heat of day and cold of night in the Abydonian desert.
The mastadge has been domesticated for the Abydonians and, as well as being used for food and clothing, aided in labor during the thousands of years the population was oppressed by Ra. It is capable of galloping at great speeds.
"Stargate" the Movie - A mastadge is the first sign of life seen by the team on Abydos, and ends up dragging Dr. Jackson directly to its masters.