The warning comes from J R R Tolkien's The Hobbit, where never laugh at live dragons survives as a piece of folk wisdom linked to Bilbo's encounter with Smaug, the dragon under the Lonely Mountain. The book was published in 1937 and Smaug became one of fantasy's defining dragons through later film adaptations. Online, the line was remixed into a harsher, profane sound clip voiced as Smaug himself, turning literary advice into a reaction sound for moments when mocking something huge, old and dangerous proves immediately foolish.