A Mermaids Tail

(I purposely wrote 'tail' as in the fish tail instead of a story tale. It's supposed to be funny or cool. However you see it.) please read enjoy!

Mermaids (Mortal enemy) Sirens
Mermaids: Half human half fish. scales end at the hips and are found on their cheeks bones and forearms. There are male and female mermaids.
Sirens: are more transparent than mermaids and have more of a water form like look to them. their scales don't end at their hips, it ends at their chests. There are no male Sirens.

Dragons (neutral, unless one comes to close to treasure or mate)
Dragons: are practically lizards with wings and special breathing abilities but are the size of a mansion or bigger.

Fairies/cousins/Elves (Mortal enemies) Unicorns/cousins/Pegusiss
Fairies: are elves with wings and as big as butterflies.
Elves: can be midgets with pointy ears or as tall as humans and with pointy ears.
Unicorns: horses with horns, the horns are only visible when the moon is out and shines on them.
Pegusiss: horses with wings and live in the clouds, only come down at night when their brothern need help.

Angels (Mortal enemies) Banshees
Angels: mix of humans and tall elves but with white feather wings.
Banshees: mix of humans and tall elves but with black hoods over their faces and black dragon wings

Werewolves (mortal enemies) Vampires
Werewolves: humans that can turn into wolves.
Vampires: humans with pale and ice cold skin.

Humans no nothing of these creatures, and there have only been 10 humans worldwide who where born with these genetics in their DNA. There is an ancient scroll that spoke of 11 humans with legends (the mythical creature DNA) in their DNA would bring together the split brothers and sisters in their great time of need to defeat the two dangers they all shared, discovery and extinction. Who is the last legend to be born and help in an elaborate plan to save the mythical dimension?

(I don't know) I guess to find out you'll have to read!