From Zelda Dungeon Wiki
This image is fan artwork depicting a copyrighted work that is likely the property of Nintendo or its affiliates. It is used with permission of the artist and we believe it qualifies under fair use with regards to its copyright, because it is a tributary work that promotes the copyrighted work and is used merely to depict and discuss it without impeding its owner's rights or profit.
This describes licensing for fanart images uploaded to the wiki.
Select the "Fanart" option in the Licensing drop-down on the Upload page.