Something Fishy About the Pope´s Hat

The Origins of the Fish Head Mitre Hat

We will see where the Pope and the Catholic Bishop's Mitre has it´s origins from:
"Adapa was a mortal from a godly lineage, a son of Ea (Enki in Sumerian), the god of wisdom and of the ancient city of Eridu, who brought the arts of civilization to that city (from Dilmun, according to some versions)."
"Adapa is often identified as advisor to the mythical first king of Eridu, Alulim. In addition to his advisory duties, he served as a priest and exorcist, and upon his death took his place among the Seven Sages or Apkallū. (Apkallu, "sage", comes from Sumerian AB.GAL (Ab=water, Gal=Great) a reference to Adapa, the first sage's association with water.)"

"it is now known that the name is the Greek form of the Babylonian Uanna (or Uan) a name used for Adapa in texts from the Library of Ashurbanipal."
-Source: K. van der Toorn, Bob Becking, Pieter Willem van der Horst: Dictionary of deities and demons in the Bible Edition 2, revised, B. Eerdmans Publishing, 1999

"Adapa -son of Ea, priest in Eridu. Also known as Uan (Oannes), the first of the Seven Sages, who brought the arts and skills of civilization to mankind."  
(p. 317. "Glossary of Deities...Adapa." Stephanie Dalley. Myths From Mesopotamia: Creation, The Flood, Gilgamesh, And Others. New York & Oxford. Oxford University Press. 1991)

Adapa is Oannes and one of the Seven "Sages" called Apkallu:

The Apkallu (Akkadian) or Abgal, (Sumerian) are seven Sumerian demigods said to have been created by the god Enki (Akkadian: Ea) to give civilization to mankind. They served as priests of Enki and as advisors or sages to the earliest "kings" or rulers of Sumeria before the flood. They are credited with giving mankind the Me (moral code), the crafts, and the arts. 

They were seen as fish-like men who emerged from the sweet water Apsu. They are commonly represented as having the lower torso of a fish, or dressed as a fish. They have also been depicted with wings, having either a human head or an eagle's head.

Fish-men figurines, the so-called "seven sages"  (apkallu), sun-dried clay, from the foundations of a priest's house in Asshur ca. 721-705 BCE (p. 18. Jeremy Black and Anthony Green. Gods, Demons and Symbols of Ancient Mesopotamia, An Illustrated Dictionary. London, British Museum, in association with the University of Texas Press. Austin. 1992. ISBN 0-292-70794-0. paperback).
Adapa (one of the Apkallu) was the son of Ea (Enki) the Sumerian Fish God

Enki was the patron God of the city of Eridu, the City of Eridu was founded by Nimrod

"David Rohl (an Egyptologist), like Alexander Hislop, identified Nimrod with a complex of Mediterranean deities; among those he picked were Asar, Baal, Dumuzi and Osiris. In Rohl's theory, Enmerkar the founder of Uruk was the original inspiration for Nimrod, because the story of Enmerkar and the Lord of Aratta bears a few similarities to the legend of Nimrod and the Tower of Babel, and because the -KAR in Enmerkar means "hunter". Additionally, Enmerkar is said to have had ziggurats built in both Uruk and Eridu, which Rohl postulates was the site of the original Babel. Enmerkar and the Lord of Aratta is a legendary Sumerian account, of preserved, early post-Sumerian copies, composed in the Neo-Sumerian period (ca. 21st century BC). It is one of a series of accounts describing the conflicts between Enmerkar, king of Unug-Kulaba (Uruk), and the unnamed king of Aratta (probably somewhere in modern Iran or Armenia). It is also notable for its strong parallels to the Tower of Babel narrative of Genesis."

Enki is just another form of Nimrod, son of Cush, grandson of Ham, and great-grandson of Noah; and as "a mighty one on the earth" and "a mighty hunter before God". This is repeated in First Book of Chronicles and the "Land of Nimrod", used as a synonym for Assyria, is mentioned in the Book of Micah.

"Nimrod figures in some very early versions of the history of Freemasonry, where he was said to have been one of the fraternity's founders. According to the Encyclopedia of Freemasonry: The legend of the Craft in the Old Constitutions refers to Nimrod as one of the founders of Masonry. Thus in the York MS., No. 1, we read: "At ye making of ye toure of Babell there was a Masonrie first much esteemed of, and the King of Babilon yt called Nimrod was a Mason himself and loved well Masons." However, he does not figure in the current rituals."

Priests in Fish robes were still prevalent even after Sumeria here are some examples: 

(picture cf. p. 15. figure 7. "Fish Gods at the Tree pf Life; Assyria, c. 700 BC." Joseph Campbell. The Masks of God: Creative Mythology. New York. Viking Penguin. 1968. Reprinted 1976)

Fish-garbed priest bas-relief on temple of the god Ninurta (Saturn) at Kalhu (biblical Calah), ca. 883-859 BCE Assurnasirpal II (p. 83. fig. 65. "fish-garbed figure." Anthony Green. Gods, Demons and Symbols of Ancient Mesopotamia, An Illustrated Dictionary. London, British Museum, in association with the University of Texas Press. Austin. 1992. ISBN 0-292-70794-0. paperback).

More Fish Symbolism: 

Dagon is crowned. Vatican keys(3-trinity) 3 arched fish(trinity) black cross

Vesica Piscis (2 circles put together to form a fish shape)

"666 is the length of a vesica, whose width is  384, or the sun’s radius measured by the tone.   If the Greek numerals from one to ten be arranged so as to correspond to the cabalistic steps and their numerical vavlues computed, we find that  EIS 215,  DUO,  474.  TREIS,  615, yield  1,304,  which is one less than the length of a vesica which will contain a circle having a circumference of 2,368, and this triad represents the three steps of the Macrocosm"
Source: T H E   C A N O N AN  EX P O S I T I O N   O F   T H E  PA G A N  MY S T E RY PE R P E T U A T E D   I N   T H E  CA B A L A   AS  T H E  RU L E   O F   A L L   T H E  AR TS B Y WI L L I A M  ST I R L I N G

1977 Vatican City 10 Lire aluminum coin with a Fish

The Pope wears a "Ring of the Fisherman" mocking 
Mark 1:17

"About the very time when the Bishop of Rome was invested with the pagan title of Pontifex, the Saviour began to be called ICHTHUS, of 'THE FISH', thereby identifying him with DAGON." (Hislop, p. 215) "The two-horned mitre, which the Pope wears…is the very mitre worn by DAGON." 
(Hislop, p. 215)