Doodnik's Cafe Patron's Species
Here is an extremely rare species of alien. To my knowledge, the only place he has appeared in all Star Wars media is one panel of the book The Lost Prince: A Droid Adventure. This character was seen hanging around in Doodnik's Cafe on Tyne's Horky. It's unknown if Tyne's Horky is his homeworld, but the appearance of the native species of Tyne's Horky is also still unknown, so who knows, this could be it (he's got my vote anyway)! Obscure, yes. But he has a great look, and seems like his species could fit right into a modern Star Wars comic.