Lord of the Rings: How Morgoth Created Dragons

The dragons of Middle-earth were some of Morgoth

The Lord of The Rings Theory: Smaug Wasn't Always a Dragon

Ancalagon the Black, Wiki

Balrog - Wikipedia

Glaurung - Tolkien Gateway

Which Prequel Has More Promise: House of the Dragon or Lord of the Rings: The Rings of Power?

All 5 Dragons in Middle-earth (The Lord of the Rings, The Hobbit, and The Silmarillion)

Where do LOTR dragons come from? - Quora

Lord of the Rings' Biggest Dragon Was Ancalagon, Not Smaug

Glaurung, The One Wiki to Rule Them All