The bulk update request #11568 has been approved by @evazion.
As a tag it's only been used for 66 posts, almost all of which are for the character Mutio. The wiki describes it as "Anything that is part human part animal. Examples include werewolves and vampires (at least the ones who turn into bats)." Vague at best, and could be easily covered under things like monster girl/monster boy, furry, and the various animal ears and related tags.