I've been noticing that the few characters Karno has drawn that repeat don't have associated tags. Not sure how to go about setting up a tag for them.
An example of some is these two, The Mink(Laura Walker) and Melody:
https://e621.net/post/show/488899

Add character:(name) through the tag editor.
Make sure that (name) doesn't already exist as a tag before you do so, because adding character:(name) as a tag changes the chosen tag's type to character.

Tagging help

Thank you!