Elves are the first and eldest race in Tolkien’s Middle-earth. They are immortal beings who do not die from disease or old age but can be killed in battle or by grief. Their spirits go to the Halls of Mandos in Valinor upon death, where they may be re-embodied after a period of rest. Elves are described as tall, fair-skinned, with often grey or bright eyes, and their hair color varies by subgroup.

Men in Tolkien's Middle-earth are the Secondborn, created after the Elves by Eru Ilúvatar. Unlike Elves, Men are mortal, meaning they age and die naturally, and their spirits leave the world after death. Physically, Men are varied but generally have rounded ears, rougher features compared to Elves, and can grow facial hair.

Dwarves in Tolkien's Middle-earth are a distinct race known for their toughness, resilience, and exceptional craftsmanship, especially in mining, metallurgy, blacksmithing, and jewelry making. Created by the Vala Aulë in secret before the awakening of Elves, they were later accepted by Eru Ilúvatar, who gave them life and decreed their unique fate.

Hobbits are a small, peaceful race in Tolkien's Middle-earth, closely related to Men but smaller in stature, typically between two and four feet tall. They have distinctive features such as tough, leathery soles covered with hair, and generally no need to wear shoes. Hobbits are known for their love of comfort, good food, drink, laughter, and simple rural living. They are skilled at moving silently and quickly when needed.

Ents are an ancient race of giant, tree-like humanoids in Tolkien’s Middle-earth, often described as "shepherds of the trees" and protectors of the forests. They are extraordinarily tall and strong, with bark-like skin, limbs resembling branches, and varied appearances based on the types of trees they are connected to.

Orcs in Tolkien’s Middle-earth are a brutish, aggressive, and malevolent race often depicted as enemies of Elves, Men, and other free peoples. They have humanoid shapes but are generally ugly, filthy, with fanged mouths, bow-legged builds, and long arms. Orcs tend to be smaller than Men on average and avoid daylight.

Trolls in Tolkien's Middle-earth are monstrously large humanoid creatures known for their immense strength but limited intellect. They are depicted as dangerous warriors, often serving the dark powers Morgoth and later Sauron. Trolls come in various breeds, such as Cave-trolls, Hill-trolls, Mountain-trolls, Stone-trolls, and Snow-trolls, each adapted to different environments.

The Maiar are a class of supernatural and angelic beings in Tolkien's Middle-earth, lesser Ainur who entered the world at its creation to help the Valar shape and govern it. They are powerful spirits who can assume physical forms and perform great works of magic, but their true nature is spiritual and immortal.

The Valar are powerful divine beings in Tolkien's Middle-earth, created by Eru Ilúvatar, the supreme god. They are the greatest of the Ainur who entered the world to shape, govern, and maintain it. Often called the "Powers of the World," the Valar dwell primarily in Aman on the western continent of Valinor and are responsible for the physical and moral order of Arda (the world including Middle-earth).

Dragons in Tolkien's Middle-earth are powerful, intelligent, and often malevolent creatures known for their immense strength, cunning, and, in many cases, the ability to breathe fire. They are quadrupedal, some with wings (fire-drakes), and others wingless (such as Glaurung). Dragons can speak and have a hypnotic power called "dragon-spell" that can influence and control others.

Barrow-wights are supernatural, wraith-like beings in Tolkien's Middle-earth. They are evil spirits sent by the Witch-king of Angmar to inhabit ancient burial mounds called barrows, particularly in the Barrow-downs region. These spirits animate the bones of dead men buried there, often former Dúnedain warriors, and use their presence to haunt and trap living intruders.

Uruk-hai are a breed of orcs in Tolkien's Middle-earth, known as elite soldiers of evil. They are stronger, taller, and smarter than typical orcs and can tolerate sunlight much better, unlike standard orcs who are weakened or harmed by daylight. The name "Uruk-hai" literally means "Orc-folk."

Huorns are tree-like beings in Tolkien's Middle-earth, existing as a kind of halfway point between trees and Ents. They are more sentient and mobile than ordinary trees but less fully sentient than Ents. Huorns dwell mainly in Fangorn Forest and are known for their eerie, unsettling movements and malevolent aura.

The Eagles, or Great Eagles, in Tolkien's Middle-earth are immense, sapient birds capable of speech. They were created or "devised" by Manwë, the King of the Valar, to serve as his messengers and spies. These Eagles are much larger than real-world eagles, with Thorondor, the Lord of Eagles, said to have had a wingspan of around 180 feet.

Ilúvatar, also known as Eru Ilúvatar, is the supreme creator and god-like being in Tolkien's Middle-earth mythology. He is the sole creator of the universe (Eä), including the world of Arda and its inhabitants. Ilúvatar created the Ainur, divine spirits who helped shape and govern the world, and he alone has the power to give true life, especially to the Children of Ilúvatar—Elves and Men.