Hybrids are created by crossing one animal species with another closely related animal species. Horses can be cross-bred with donkeys and zebras.
These hybrid types are not breeds, but they resemble breeds in that crosses between certain horse breeds and other equine species produce characteristic offspring.
Offspring of a hybrid mating are often sterile, but not always.
Naming of hybrid species is usually a combination of parts of the parent species names, but there are exceptions to this rule. Usually part of the male species' name comes first in the new hybrid name.
Hybrid animals are often referred to by a portmanteau formed by combining the names of the two parent species: traditionally the father’s species forms the first part of the name, hence: male Zebra + female horse -> Zorse and male horse + female zebra -> Hebra.