The Merpeople's Song

The Merpeople's Song was what the Golden Egg from the dragon in the first task sang when opened underwater. As the song was from merpeople, who can only talk and sing underwater, when opened above ground, the egg's song turned into a loud, schreeching scream. The champions had to decipher that the scream was dehydration, and place the egg in water.

The Egg's Song- Book
Come seek us where our voices sound, We cannot sing above the ground, And while you're searching ponder this; We've taken what you'll sorely miss, An hour long you'll have to look, And to recover what we took, But past an hour, the prospect's black, Too late it's gone, it won't come back.

The Egg's Song- Film
Come seek us where our voices sound, We cannot sing above the ground, An hour long you'll have to look, And to recover what we took

Trivia

 * In the film adaptation, the 3rd, 4th, 7th and 8th lines are cut, and replaced by other lyrics.
 * In LEGO Harry Potter: Years 1-4, the golden egg is floating over fire.
 * In the book, the egg is with other dragon eggs, while in the film, the egg is alone.