Beast Quest: Skor the Winged Stallion by Adam Blade

Tom froze. A horse's body, as black as coal, towered above him. Silver sparks flashed from its eyes. The Beast reared on muscular hind legs, churning the air with gleaming hooves. His mane was as white as snow and his tail floated in the air like strands of emerald seaweed. Skor gave a deafening roar and unfurled giant, glossy wings. He launched himself into the air. Tom staggered backwards into Elenna. The underside of the Beast's feathers shimmered purple like an exotic seashell and the tips looked as if they had been dipped in gold.Tom spotted a shimmer of emerald green in one of the golden hooves. A jewel the size of his fist was embedded there, just like the red gem in Torgor's axe.