Generally speaking, fan art does not belong on wikis. This wiki's policy is "Fan art should not be uploaded to the Wiki". Please don't add fan art to articles. If you do find fan art already in an article, you should remove it.
Unless the wiki has dramatically changed in the last two months, then the statement that "There is a lot of fan art in this wiki" is false. There is a lot of book art, including from foreign editions, but that is not fan art (e.g. File:CafeRussian.png is from the Russian edition - it is not fan art).