A little something about the molds:

~ Dancer. Her first horse came in the early '70s and was, as mentioned above jointed everywhere for "natural" posing. When handled right you could make galopping sounds with its hooves. All plastic. Later models had rooted mane and tail.
~ Western. Midnight and Dallas were sturdy horses with hooves firm to the ground and one hoof lifted. European versions of Dallas were made with the "dancer" or "trottler" mold and came in a variation of colors (white, tan, brown, black)
~ Foals. Dallas' adorable baby foal Dixie was the first.
~ Honey. Skipper's pony, made in a small likeness to the Western horse, but of course smaller.
~ Dressage stallion. The big handsome stallion. Champion is one. These are mostly in a dark color with black mane and tail.
~ Trottler. This is the most common horse type and used for most of Barbie's carriages and carts. It has a floating, running style.
~ Walker. Hard to put a name on this one. A standing type horse with slightly lifted back hoof.
~ Walker. Sprint or High Stepper was Barbie's first horse that walked all by himself. Worked on batteries and he wiggled around...
~ Ponies. There was a bunch of ponies in the '90s for Stacie and Kelly/Shelly that each had a movement of some sort. Obvoiusly made different but overall they had the same look.
~ Nibbles. I haven't got this horse in any way so I cant give it or the mold another name. Nibbles had a magnet in the muzzle and could bend his head.

There are lots more molds and versions, especially in recent years but right now this is what I can list.

Most of my pets are bought used and are missing parts of their accessories, rubbed on noses etc. Some have been put under a kid's love for hair dressing and therefor been cut. 

Here is a small portion of them all.