Issue with "lack_hair" tag

There is a tag in the database called lack_hair, which I can assume is just a misspelled black_hair. But while searching for lack_hair normally shows no results in the post index, searching for it in the Tags section shows only one post with this tag.

Because of this, I can't remove lack_hair myself and keep it out of the autocomplete in DanbooruUp. Is there another way to get rid of this tag?

it's probably just cached, cached tag counts I believe are updated daily. If someone entered a misspelled tag, and it happened to be at the wrong time and your DanbooruUp happened to update when it was cached in the system this can happen. It should go away by itself after a day or two on its own. There are no deleted posts under that tag that might force it to stick around.