" At the end of the world there lies a mountain so high it makes you dizzy even to think about it. It is as black as soot, as smooth as silk, terribly steep, and where there should be a bottom, there are only clouds. But high up on the peak stands the Hobgoblin's House, and it looks like this." And Snufkin drew a house in the sand.
"Hasn't it got any windows?" asked Sniff.
"No," said Snufkin, "and it hasn't got a door either, because the Hobgoblin always goes home by air riding on a black panther. He goes out every night and collects rubies in his hat."
"What did you say?" asked Sniff, with his eyes popping out of his head. "Rubies! Where does he get them from?"
"The Hobgoblin can change himself into anything he likes," Snufkin answered, "and then he can crawl under the ground and even down onto the sea bed where buried treasure lies. "

― Tove Jansson , Finn Family Moomintroll (The Moomins, #3)