It is called a centaur.
If the upper half is human with the lower half horse and the horse section has all four horse legs, it is indeed a centaur.
If it has the upper half of a human with the lower half of a horse but only 2 legs like a satyr it is a Sileni.
There are also horse-headed men but I can not find the names for them.
There is also the deity Hayagriva in Hinduism and Buddhism that has a white horse's head and a human body and is pictured as seated on a lotus.
The cross of these two breeds is just a cross until it's registered as foundation stock with the Pintabian horse registry.
The product of a horse/donkey breeding is a mule.
We can do this with animals as well. They are called hybrids. Some are not fertile. An example of an animal is a mule: a cross between female donkey and a male horse. A cross between a male donkey and female horse produces a hinny which is considered worthless.
We can do this with animals as well. They are called hybrids. Some are not fertile. An example of an animal is a mule: a cross between female donkey and a male horse. A cross between a male donkey and female horse produces a hinny which is considered worthless.
A common term for a cross between a human and a vampire is a "dhampir." Dhampirs are often portrayed in folklore as having abilities like heightened senses or resistance to vampires.
an unborn horse fetus, just like an unborn human fetus.
Typically, a horse is either wild or tame, and there is no middle ground. I suppose you could call it semi-feral, semi-wild or semi-tame. If you mean a horse that lives with humans, but has not been gentled yet, you would refer to it as an unbroken horse. If you mean what is a horse that is half mustang or brumby called, then you would call it a mustang cross, or a brumby cross.
A "stroon"
That is not possible. A crossbreed between a donkey and a horse is a mule. However, because the donkey and the horse are two different species, the mule is infertile, meaning it cannot reproduce. Because it cannot reproduce, it cannot mate with a donkey, and as such a crossbreed cannot exist.
In Greek mythology, the centaurs are a race of creatures composed of part human and part horse.
You refer to a boy alien as "he" or "him" just as you would a human boy, or a horse or a garble.
An AraAppaloosa (Arabian / Appaloosa cross) can be registered with it's breed association, the AraAppaloosa Foundation Breeder's International. They do not have a website, so you would have to write to them or call. Also if the horse is a first generation crass between the two breeds, you could possibly register it as a half Arabian with the Arabian Horse Association. The Appaloosa Horse Club may also offer some sort of 'appendix' registry for this cross.