Talk:Necro Armor/@comment-67.181.23.127-20120115064802/@comment-4085927-20120115071345

There are 3 bosses that are harder than Skeletron, they become available once you enable Hard Mode. Killing the Wall of Flesh is what enables Hard Mode. So you can access the dungeon after beating Skeletron, get the bones then go to the Underworld to fight the Wall of Flesh. You may be confusing Skeletron with Skeletron Prime.