There are mainly different interpretations.
In 2 books titled Black Unicorn, the lengendary animal is known to be a fierce and frightful terror though later to be found out otherwise: in one story it is the shadow of all the imprisioned unicorns struggling to be known and freed and the other I'm not too clear about but is somehow wanting to return home.
Other interpretations included are in Anime as in the twelve kingsoms anime series the Black Unicorn is a highly prized unique creature endowed with additional sacred powers though prone to sadness and innerturmoil. In this series the Black unicorn is called a Black Kirin used interchangeable by some as Unicorn. This character/creature, in this series it is both, is both regal, just and is assigned to some land mountain that is fabled where the dead go where they die because of the it was thought to bring luck.
Some D&D type adventure games the creature is a demon and not a unicorn at all. Something of the sort that most likely spews smile or something and thus is associated with hell and the satan.
In more associations they are a variation of the White Unicorn i.e. Blue Unicorn (a song by a cuban singer) Pink Unicorn, invisible unicorn, etc.
My personal definition would be associations with Love, Shade, Yin, Water, Innocence, Romance, and Beauty.
Thank you for the post

Here is a song about a Black Unicorn.
( www.heatherlands.com/seafire...mes.html )

Black Unicorn
( Music & Lyrics: Heather Alexander )
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I am he that knocks on your windowpane,
I am he that stalks the night
I am he with silver shot through my mane,
you'll dream of me with fire-eyes bright
If you ever meet me standing there,
you'll wish that you were never born
I'll seize your soul and strip it bare,
I am the Black Unicorn

My horn is forged of silver fire,
my shoulders bear leathern wings
I am the nightmare of your own desire,
I am the song that the Devil sings
Hellfire dancing in my eyes,
my coat is as black as coal
Mortals are so quick to hypnotize,
and then I merely take your soul

Teeth sharp as daggers cooled in the snow,
and hooves that burn through the ground
Follow me not where I lead you to go,
for then your soul will be devil-bound
There is but one who rides my back,
and keeps his soul ever free
His heart is cold and will not crack,
and he is as cursed as me

REPEAT FIRST VERSE
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