User blog comment:Eitan101/Cant Beat Eater of Worlds/@comment-4776391-20120213121725

You could possibly get a Hunter Potion, I found them useful as you can see where he's going to pop up. You should be ready, just make sure you get a lot of ammo for the Musket. If possible, get horizontally from him and fire non stop at the head, you should destroy it over and over and eventually get rid of the whole worm.