Answer:
Who lives in a house with one bedroom, 50 hallways, and ghosts lurking everywhere?
Thousands lay up gold within this house, But no man made it. Spears past counting guard this house, But no man wards it.
Without a bridle, or a saddle, across a thing I ride a-straddle. And those I ride, by help of me, though almost blind, are made to see.
Long and slinky like a trout, never sings till it's guts come out.
What is that which, though black itself, enlightens the world without burning?
Dark, feathery, and popular in Baltimore and fantasy books.