I believe it was one of several ponies that
came from a local collector's collection, and therefore may
have been kept in package deliberately. But whether it was
found here or imported from overseas is unknown. A lot of
German packaged ponies were sold on clearance in the UK
towards the end of the line, so it is possible that happened
here. We'll probably never know for sure, but I did find my
Baby Lucky Leaf loose here as well.
Whether this set saw a release anywhere else in Europe is
unclear. I have never seen a bordered 1990 card in any
language other than German, but I am not sure whether there
were imports of the American boxed version in other places.
One other weird thing that exists, but which
is NOT official My Little Pony and was made as a knock off,
are some fakie versions of the pretty pals. These were known
to be sold in the Netherlands and in Belgium, and they used
the moulds of the Pretty Pal set quite convincingly - but
the plastic feels a lot softer and there is no Hasbro stamp
on the hooves. The colouring is different and so, sometimes,
is the symbol.

White Woolly Fakie (left) and green Leafy fakie (right)
Leafy image from Shivhae