"I'd also be fairly surprised if it turned out to qualify as harm, especially given the reasons why turning someone into a sparrow does," he says. "On the other hand - turning someone into a sparrow doesn't make them mortal, right? Which sparrows traditionally are. So turning a mortal into a fairy might not accomplish the reverse, in which case it would be a much less useful trick. Still handy if you really want wings, I guess. Hmm, is it possible to turn a fairy into a different kind of fairy, with a different set of wings?"