Bruin

Two young brothers, the sons of a Russian nobleman, ask their father if
they may spend a while travelling the world. He agrees, but lays down
two conditions: one, that they should bring back the skins, in good
condition, of every species of bear there is; two, that they should
proceed from east to west, or from west to east, without doubling back
on their tracks, except, of course, while actually engaged in the chase.

The boys, for they are still in their teens, accept the conditions, and
set off westward, visiting all sorts of interesting places in Europe and
elsewhere, and gathering numerous bearskin trophies on the way. Oddly
enough they never go to Australia, but maybe the Koala bear is not a
bear, within the definition of the word.

They take with them an old retired guardsman, Pouchskin, who looks after
them generally, and takes a lot of the knocks of the journey.
Eventually they return home, where the boys are lauded as heroes,
and Pouchskin returns to obscurity.