How's this as a theme for the Khraken attack?
http://www.youtube.com/watch?v=1yCLDVDXlGY just imagine the Akonians running in fear from them, getting taken down, bitten. The pain they'd feel as the mandibles dig into them, swarming on them. They see their friends die, and the great beast lumbers over the plains outside the village, chrushing the trees... hope is lost... And then the bomb drops.