What does Ezekiel 32:2 mean?

Son of man, sing a funeral song for Pharaoh, king of Egypt. Tell him: You thought you were like a young lion among the nations, but really, you’re more like a sea monster thrashing around in your rivers, muddying the water with your feet and stirring up the streams. Ezekiel 32:2 - Modern Text Bible

(God tells Ezekiel to mourn for Egypt, exposing Pharaoh’s self-image as false and destructive.)