Olláparo

The Olláparo or Alláparo is a Galician mythological being. It is a species of giant cannibals that only has one eye in the middle of the forehead, rude and fierce, very wild and voracious, great eater, who lives in the caverns in the forests and in the mountains, especially in the mountain of Lugo and Ourense. Sometimes the Olláparo has two eyes, one on the forehead and another on the nape. Your women, they're even worse than they are.

It resembles the classic Cyclops, or the Fomorian of Irish mythology, (also with two eyes located in the same way), being the most famous Balar. The back eye of Balar was terrible, as it provoked evil eye and can be compared with Medusa.