PLEASE for the love of God, don't post sprites for NPCs or other things that haven't been accepted yet or don't have a visual design yet! There's a chance you'll be wasting your time, because the npc may or may not make the cut.
Things on the need list thread are priority. It's short for now, but it can potentially get much larger.
Also, there is a specific format to sprites that we look for. We will not accept sprites unless they are properly formatted. To see that format, see the Link sprites:http://zfgc.com/forum/index.php?topic=39905.0