As I've never come across any images
of the Growing Hair ponies, so it's always possible
that they were never produced, or only at a very
small level.
I would guess that their hair could
grow in length via a winding mechanism controlled
by a couple of the decorations on the ponies side.
In the case of the left image, it would be either
the flower above its front left leg or the butterfly
on its left hip.
See Other
Ponies for some prototype images.
If you know anything about this
set or have any images I can use here then please
contact
me!
or eBay
