This constellation came introduced for the first time from Babilonesi
and Sumeri approximately 4 millenia ago and represents one strange
creature with the head, anterior legs and bust of goat, and the tail
of fish.
For the Greeks it was Pan, the God of the country. Originally it had
all the four legs of goat and he took delight hunting the women and
sleeping. Its yell was so much high to scare the people and is for
this that the word “panic” has been coined.
A day tried to catch a nymph, but this was transformed in  a group of
canes that to blowing of the wind emitted a so delicious sound that
the God, reuniting some of various length, formed the syringe, or
bagpipe of Pan.
There are three interpretations on the mutation of its aspect:
according to Eratostene he helped the gooddes in the fight against
Titaniums, blowing a shell and therefore putting them in escape.
Because of the shell its posterior part would have been transformed in
fish tail.
According to Igino, instead, the mutation would be due to the fact that
the God launch against the enemies some shellfishes, but that is little
convincing.
According to an other interpretation, Pan helped a second one time the
goddess when Gea (the Mother Earth) sent against of they the Tefeo monster:
the God at first advised the others of changing itself in animals in order
to trick it. He sheltered itself in a river and transformed its posterior
part in a fish. Zeus faced it but it left the nerves of the legs, than
they were given back to it just from Pan and Ermete: the God therefore
could resume the fight and he succeeded to strike with lightning the
monster, that it came then imprisoned in Mont Etna, whose eruptions were
considered its breaths. Zeus in memory of its aids put Pan in the sky.
The star alpha capricornii, correspondent to the snout, is called also
Algedi or Giedi, name that derives from the Arab al-jadi, “the kidskin”.
Delta capricornii calls also Deneb Algedi, “kidskin tail” in Arab.