Sauron has appeared in various forms since creation. He can transform into angel, wolf, serpent, monster, vampire, and Necromancer. By Second Age, he lost his body twice and became increasingly humanoid
Sauron created the Eye after the Downfall of Númenor. The Eye was projected as Sauron's mental image showing unceasing vigilance. It was displayed as an emblem on Orcs' weapons and used as a symbol
Elves have roots in Old Norse word "álfr". Fantasy worlds of elves have captivated people for centuries. Norwegian elves called "nisse" inspired Christmas elf depictions
Rohan is a grassland kingdom in Middle-earth, bordered by Fangorn forest and rivers. Capital Edoras sits on hill in White Mountains, with Meduseld as golden hall. Kingdom divided into East-mark and West-mark, ruled by marshals. Rohirrim speak Old English, called their land "Riddermark"
Tolkien adopted "orc" from Old English "hell-devil" and "demon-corpses". The term "orc" likely derived from Latin "Orcus" but Tolkien questioned it. Orcs were described as corrupted elves, bred by Morgoth, or turned evil
Melkor was the most powerful Ainur before Middle-earth's creation. He sought to fill the Void with sentient beings but couldn't find the Flame Imperishable. His disharmonies created chaos that corrupted all Middle-earth