I think the Namba Pamba Pah Poozi is the most overlooked creature of all, because nobody has ever seen it, smelled it, touched or even heard of it until now.
And someday, the hoogula (a mythical creature I made up, who is in my book, The Wish Thief), will be so well known it'll be as generic as a werewolf or vampire. Hey, I can dream, can't I?