Terry Pratchett, Carpe Jugulum (1998)
Terry Pratchett, now sadly dead before his time, is famous for his Discworld novels, of which this is one.
Discworld is an alternate world, where the laws of physics are very much other. For one thing, Discworld is flat – a disc, like it says on the tin.
It is a giant disc being carried through space on the back of four mighty elephants, who stand on the back of an immense turtle swimming through space. Also, magic is real on Discworld.