Here are some terms you might see used:
* Kitsune: This is the Japanese word for fox, and is often used in stories involving fox spirits.
* Vulpine: This word means "of or relating to foxes," and could be used to describe a fox-human hybrid.
* Foxling: This is a more general term for a young fox, but could also be used to refer to a fox child.
Ultimately, the name for a fox child depends on the specific story or world you're working with.