The Giant lobster lives in the wrecked pirate ship directly north of the Alice's husband's farm, which is west of Port Phasmatys. It emerges from a chest when players attempt to open it. It must be defeated in order to obtain the Map scrap contained within its chest. It attacks only with melee and is very weak. If you take too long to kill it, it disappears and you'll have to fight it all over again. It can only be killed once. Oddly, like the Giant lobsters fought in The Slug Menace, it counts for Scorpion slayer tasks.