Ogri

The Ogri were a species of silicon-based creatures native to Ogros. They looked like large rocks, usually taller than a human but irregular in shape. They were large, slow and heavy, sometimes weighing as much as 3.5 tons, but they could take a lot of damage, both energy-based and physical. When they were awake, they would glow and make a loud rumbling noise. Like other silicon-based lifeforms, they broke down into grit when killed and also left silicon behind when they moved. They fed on various types of proteins which were common on Ogros. When on Earth, the Ogri had to rely on the globulin in blood, which they could absorb by touch. Ogri were not shown to communicate and did not show any signs of intelligence. Ogri had long lifespans, living for thousands of years.

Cessair of Diplos took three Ogri from Ogros, which she used for protection and to impress the humans of Earth. These Ogri waited with the Nine Travellers until they were awoken by Cessair or her followers. (DW: The Stones of Blood)

Augmented Ogri were used by the Galactic Federation as doormen. (NA: Legacy)

At least one Ogri was discovered on Earth prior to 1983, and ended up in the care of Isaac Summerfield in Little Caldwell. It resided in the cemetery and was routinely fed blood to keep it docile. It was instrumental in saving Little Caldwell from the attention of NATO, by killing a rogue NATO commander responsible for a number of abductions (both alien and human). (NA: Return of the Living Dad)