An Alp Luachra (also spelt Alp-luachra or Alpluachra), also known as a Joint-eater or Just-halver, is an evil, greedy jinni from Irish mythology. When a person falls asleep by the side of a spring or stream, the Alp-luachra appears in the form of a newt and crawls down the person's mouth, feeding off the food that they had eaten. In Robert Kirk's Secret Commonwealth of Fairies, this creature feeds not on the food itself, but on the "pith or quintessence" of the food.
Douglas Hyde's Beside the Fire tells of how a person got back at an Alp-luachra by eating large amounts of salted meat and sleeping near the stream. The Alp-luachra fed upon him, but jumped to the water in thirst.