Help solve this riddle!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I saw a strange creature, a bright ship of the air beautifully adorned, bearing away plunder between her horns, fetching it home foray. She was minded to build a bower in her stronghold, and construct it with cunning if she could do so. But then a mighty creature appeared over the mountain whose face is familiar to all dwellers on earth: he seized on his treasure and sent home the wanderer much against her will: she went westward harbouring hostility, hastening forth. Dust lifted to heaven: dew fell on the earth, night fled hence: and no man knew thereafter, where that strange creature went. What are these creatures?????????