'The Yak'

As a friend to the children
  commend me the Yak.
You will find it exactly the thing:
  It will carry and fetch, you can ride on its back,
Or lead it about with a string.

The Tartar who dwells on the plains of Thibet
  (A desolate region of snow)
Has for centuries made it a nursery pet,
  And surely the Tartar should know!
Then tell you papa where the Yak can be got,
  And if he is awfully rich
He will buy you the creature --
  or else
    he will not.
(I cannot be positive which.)


 	-- Hillaire Belloc