Monster aqueron

If you have children, or you like cross-reference readings, The Book of the Imaginary Beings by J. L. Borges is a must-have (that linked electronic version in english has extraordinary illustrations my worn-out original in spanish doesn't have). Was the book that pushed the pleasure of reading into me when was a child, all those references to ten thousand other authors and books is a universe to follow, one star to another; Borges always have that.

Now... is this giant monster dead? Someone knew? Only one person saw it... think I know that person.

Only one person, one time, ever saw the monster Acheron; this took place in the twelfth century in the Irish town of Cork.

The original version of the story, written in Gaelic, is now lost, but a Benedictine monk from Regensburg (Ratisbon) translated it into Latin, and from this translation the tale passed into a number of languages, among them Swedish and Spanish. Of the Latin version there are some fifty-odd manuscripts extant, agreeing in all the essentials.
Visfo Tundali (Tundal's Vision) is the story's name, and it has been considered one of the sources of Dante's poem. Let us begin with the word "Acheron." In the tenth book of the Odyssey it is one of the rivers of hell, flowing somewhere on the western borders of the inhabited world. Its name is reechoed in the Aeneid, in Lucan's Pharsatia, and in Ovid's Metamorphoses. Dante engraves it in a line: Su la trista riviera d'Acheronte ("On the sad shores of the Acheron") .
In one myth, Acheron is a Titan sutfering punishment; in another, dating earlier, he is placed close to the South Pole, below the constellations of the antipodes. The Etruscans had "books of fate" that taught divination and "books of Acheron" that taught the ways of the soul after bodily death. In time, Acheron came to stand for hell. Tundal was an Irish gentleman, well-mannered and brave, but of hardly irreproachable habits. He once fell ill while at the home of a lady friend, and for three days and nights was taken for dead, except for a bit of warmth in his heart. When he recovered his senses, he told that his guardian angel had shown him the lands beyond this world. Of the many wonders he saw, the one which interests us here is the monster Acheron. He is bigger than any mountain. His eyes flame and his mouth is so large that nine thousand persons could fit in it. Two damned men, like pillars or atlantes, prop it open; one stands on his feet, the other on his head. Three throats lead inside and belch undying fire. From deep in the beast's belly comes the continuous wailing of the countless lost souls who are being devoured. Devils tell Tundal that the monster is called Acheron. His guardian angel deserts him, and Tundal is swept inside with the others. There he finds himself in the midst of tears, darkness, gnashing teeth, fire, unbearable burning, icy cold, dogs, bears, lions, and snakes. In this legend, hell is a beast with other beasts inside it. In 1758, Emanuel Swedenborg wrote: "It has not been granted me to perceive Hell's general shape, but I have been told that in the same way that Heaven has a human shape, Hell has the shape of a devil."

J.L.Borges, The Book of the imaginary beings.