<P> The following is an overview of the fictional peoples and races that appear in J.R.R. Tolkien's fantasy world of Middle - earth . </P> <P> See also Vala (Middle - earth) and Maia (Middle - earth) </P> <P> Angelic spirits created by Eru Ilúvatar at the Beginning . The Ainur were divided into two groups--the Valar, Guardians of the World who resided in the Undying Lands of Valinor outside the circles of Arda, and the Maiar, lesser spirits who served the Valar . While most Ainur did not technically live in Middle - earth, some Maiar such as the Istari Wizards, Melian, and the Dark Lord Sauron assumed mortal forms to help or hinder the peoples of Middle - earth . </P> <P> The race of Dwarves preferred to live in mountains and caves, settling in places such as Erebor (the Lonely Mountain), the Iron Hills, the Blue Mountains, and Moria (Khazad - dûm) in the Misty Mountains . Aulë the Smith created Dwarves; he also invented the Dwarven language, known as Khuzdul . Dwarves mined and worked precious metals throughout the mountains of Middle - earth . The seven different groups of Dwarf - folk originated in the locations where the Seven Fathers of the Dwarves first awoke before the First Age . The Petty - dwarves were smaller and more unsociable Dwarves of several houses, which had been banished in ancient times . They were aggressive, and fierce in battle . </P>

What are the monsters called in lord of the rings