Since I've previously noted our group seems to like lists, let's talk about some magical animals you could use to make a good story better.
Afrit: Afrit are the most powerful Arabian Djinn, and they are evil. They can take any form. Afrit translates as "unclean spirits".
Barometz: Half plant, half animal and shaped like a sheep, it screams when picked and blood flows from its stems.
Dryads: Dryads are tree nymphs, the tree in question most often oak. They are shy creatures, tied to their homes and supernaturally long-lived. The hamadryads were so connected to their trees that if the tree died, its hamadryad associated died too.
Fuaths: Scotland's waters are said to be home to these creatures who are green, have no noses, with the mane and tail of a yellow horse. They are said to drown unsuspecting swimmers.
Hippocampus or hippocampi: Known as horses of Poseiden, these creatures were said to have the front of a horse and the rear-end of a fish/whale, kind of like a mer-horse.
Jotans: In honor of Thor, the new movie, the Jotan are Norse frost giants who live in northern Europe.
Nia: Nia are air spirits from Africa, prayed to before journeys.
Scylla: A scylla was said to be a young girl raised by wolves who was used by a man she thought loved her, and drowned trying to swim to his boat. When she sank into the water, Poseiden changed her into a nymph, only it only worked on her upper half. Her lower half changed into a six-headed wolf.
Ziz came from chaos at the beginning of time as a giant bird.
Hopefully, you've gotten some good ideas - or at least learned something today.