" He takes parties up and down the river in the season and points out crocodiles and a stray hippopotamus or so to them. I believe that he keeps a tame one which is trained to bite pieces out of the boat on occasions. Then he fends it off with a boathook, and the party feel they have really got to the back of beyond at last. "

― Agatha Christie , The Man in the Brown Suit (Colonel Race #1)