Is not usual, but can happen in some species Not necessarily a clone because sometimes happens in several steps. For example, horse x donkey hybrids are steril

Is not usual, but can happen in some species Not necessarily a clone because sometimes happens in several steps. For example, horse x donkey hybrids are sterile in principle, but if just by chance they produce an ovule keeping only the DNA of one of their parents, it can be fecundated. A female mule can deliver a foal that is either a pure horse or a pure donkey, never another mule.