S'Yahazah, known as the Great Egg Bringer, is the name given to a god worshiped by the Gorn species. She was known also as the Mistress of Fertility and was the most important figure in Gorn noble religion.
According to myth, S'Yahazah and the "Great Father" were responsible for the creation of the Gorn species and were, thus, their founders. However, Gorn belief would place more emphasis on the Great Egg Bringer for she protected the young Gorn from the Great Father who attempted to devour the eggs that would have given birth to the Gorn species. S'Yahazah banished the Great Father into the coldness of space after which he was never worshiped again.
The Mistress of Fertility has been known to take the eggs of all Gorn who have a blue-yellow scale coloration and safeguard them against harm. This is because those Gorn who possess such a coloration are believed to be marked for nobility and spiritual purity among their race. She has also been known to provide fertilization methods that ensure maximum genetic potential. This has resulted in certain hereditary Gorn families gaining a large number of Blue-Yellow Gorn born and is a symbol of Gorn strength.
It's been noted among the Gorn that S'Yahazah has spoken out against the leadership of the Gorn Hegemony which has caused some to wonder whether they will act in internal Gorn politics. (TOS video game: Starfleet Command)
In 2382 the terraforming device known as Brahma-Shiva was believed by members of the Gorn Technology Caste to be a reincarnation, or potentially the original, S'Yahazah because of its ability to shape planets and its presence near Gorn territory. In order to safeguard the planet Hranrar, an away mission was authorized to the terraforming device with a mission to destroy it before it could be used on the defenseless planet. During the mission the consciousness of S'Yahazah migrated into the mind of Starfleet Commander Tuvok of the USS Titan via a Mind meld and the terraforming device was destroyed shortly afterward. (ST - Typhon Pact novel: Seize the Fire)