If you are looking for text to accompany a 1920x1080 wallpaper of this painting or fan art, you can use the iconic in-game status message that appears when the boss is about to spawn naturally: Other thematic text options include:
(A reference to its mechanical worm nature) 1920x1080 The Destroyer Painting : Terraria
(The material dropped by the boss upon defeat) If you are looking for text to accompany