Ogres

Ogres were monstrous and destructive creatures of legend and folklore. In fact, it is doubtful whether Ogres ever existed in Middle-earth. Tolkien mentions them only once, in The Hobbit, during Bilbo's Riddle-game with Gollum. In his attempt to solve Gollum's fifth riddle, Bilbo '...sat in the dark thinking of all the horrible names of all the giants and ogres he had ever heard told of in tales...' Since no ogre is ever again mentioned, it is entirely possible that they were a mythical race even to the inhabitants of Middle-earth.