Thread:KOTails/@comment-24394544-20180830122307/@comment-26447088-20180831024906

The wiki isn't that picky with ratio, since the artwork is usually in the same ratio anyways. As for the picture format, what I use is paint.net and Save As in .PNG

You could also use a different image converter too, if you have it available. Simply changing the file extension doesn't work I believe, and the wiki won't accept it if the actual file type is different from what it's tried to be uploaded as.