Mug Ruith is a figure in Irish mythology

Irish mythology

The mythology of pre-Christian Ireland did not entirely survive the conversion to Christianity, but much of it was preserved, shorn of its religious meanings, in medieval Irish literature, which represents the most extensive and best preserved of all the branch and the Historical Cycle. There are...

, a powerful blind druid

Druid

A druid was a member of the priestly class in Britain, Ireland, and Gaul, and possibly other parts of Celtic western Europe, during the Iron Age....

 of Munster

Munster

Munster is one of the Provinces of Ireland situated in the south of Ireland. In Ancient Ireland, it was one of the fifths ruled by a "king of over-kings" . Following the Norman invasion of Ireland, the ancient kingdoms were shired into a number of counties for administrative and judicial purposes...

 who lived on Valentia Island

Valentia Island

Valentia Island is one of Ireland's westernmost points, lying off the Iveragh Peninsula in the southwest of County Kerry, Ireland. It is linked to the mainland by the Maurice O'Neill Memorial bridge at Portmagee, as well as by a ferry which sails from Reenard Point to Knightstown, the island's...

, County Kerry

County Kerry

Kerry means the "people of Ciar" which was the name of the pre-Gaelic tribe who lived in part of the present county. The legendary founder of the tribe was Ciar, son of Fergus mac Róich. In Old Irish "Ciar" meant black or dark brown, and the word continues in use in modern Irish as an adjective...

. He could grow to enormous size, and his breath caused storms and turned men to stone. He wore a hornless bull-hide and a bird mask, and flew in a machine called the roth rámach, the "oared wheel". He had an ox-driven chariot

Chariot

The chariot is a type of horse carriage used in both peace and war as the chief vehicle of many ancient peoples. Ox carts, proto-chariots, were built by the Proto-Indo-Europeans and also built in Mesopotamia as early as 3000 BC. The original horse chariot was a fast, light, open, two wheeled...

 in which night was as bright as day, a star-speckled black shield with a silver rim, and a stone which could turn into a poisonous eel

Eel

Eels are an order of fish, which consists of four suborders, 20 families, 111 genera and approximately 800 species. Most eels are predators...

 when thrown in water.

Stories about Mug Ruith are set in various periods of Irish history.