The Kriosians are a humanoid species from the planet Krios Prime. They look the same as their ancestors, the Valtese.
They are known for the somewhat randomly born empathic metamorphs. Male metamorphs are more common then female metamorphs. It takes seven generations for a female metamorph to be born.
Female metamorphs are taken from their parents at the age of four. They are taken to a royal village. It is here they learn about literature, history, art, and sex.
The Kriosian empire was once ruled by two brothers, Krios and Valt. The ruled the empire from the Temple of Akadar. The Empire fell apart when they both fell in love with Garuth.
By the 22nd century, the Kriosians were under the rule of the Kriosian Sovereign Dynasty. The family was known on hundreds of worlds. Their leader was known as the First Monarch.
In September 2152, First Monarch Kaitaama was kidnapped and held for ransom. This would lead to first contact with Starfleet. The NX-01 Enterprise saved her when Lieutenant Commander Charles and she escaped from their captors.
The Klingons would establish a colony on Krios sometime before the mid-24th century. In 2367, the Kriosians would fight the Klingon Empire for independence.
The Kriosians and the Valtese were at war. The Kriosians went on to heal the wounds with the Valtese. In 2368, the Kriosians went on to make peace with the Valtese. A marriage took place on the U.S.S. Enterprise-D between Kriosian Kamala and Chancellor Alrik of Valt.