Aliasing itsded → fernut
Link to alias

Reason:

The artist does not appear to go by the alias "fernut" anymore, and all of their currently maintained accounts are under the name "dedreds" or "dedred" and variations of such. "Itsded" is an alias found on multiple sites, including Tumblr (though the blog is now deactivated) and other boorus like rule34.

Strangely enough, while the wiki page does list "itsded" as one of the aliases, it does not function as such in searches, bringing up no results. "Itsded," itself, is its own wiki page, despite having no posts attached. I don't recall if and when it was replaced by "fernut" as the artist's tag.

To this end, "ded_reds" and "dedreds" should probably also be aliased to "fernut." I did find one of their more recent posts tagged as "ded_reds," their Twitter handle, so I believe this would help avoid further confusion.

Current:
https://twitter.com/ded_reds
https://dedreds.newgrounds.com/

EDIT: The tag alias itsded -> fernut (forum #269818) has been rejected by @NotMeNotYou.