About Ka-en-ankh Nereru / Ka-en-Ankh-nereru / Ka-en-Ānkh-nereru
Ka-en-ankh Nereru was the cosmic serpent of ancient Egypt described in the Book of the Coming Forth into Day.  In the twelfth section, or hour, of Tuat, the underworld, called Maa-nefert-Ra, the deities tow the boat of Ra through the serpent Ka-en-ankh Nereru.  Not over the back of a serpent or through a waterway Ra traversed the innards of the serpent.  When the celestial ship reached the horizon every night,  Ra and his companions entered the tail of Ka-en-ankh Nereru and over the course of the night, they pass through to emerge from the mouth of Ka-en-ankh Nereru into the light of day. 
When Ra emerged from Ka-en-ankh Nereru's mouth, the deity was rejuvenated and ready to being his daily journey through the skies once again. 
For more information on footnotes and references, please see the bibliography.