Flying Fish

"Flying Fish" are enemies that appear in Phantom Hourglass and are one of the first enemies to begin appearing upon the Overworld, starting to appear after Eddo's Cannon has been purchased. They rise out of the Great Sea of the World of the Ocean King, hovering in place for a few seconds before dive-bombing the S.S. Linebeck. They can be killed in one hit from the cannon.

The Legend of Zelda: Phantom Hourglass
They will occasionally launch themselves out of the water and hover above the vessel Link's aboard - Linebeck's steamboat, the S.S. Linebeck - before attempting to dive-bomb it. They can easily be killed with a single cannon shot by tapping the lower screen on the Nintendo DS.