Minecraft wiki entry for Defeating_the_ender_dragon, associated text: All players begin the ender dragon fight with eyes of ender, because they are needed to locate and activate the end portal, which is found in a stronghold. To make one, you need one ender pearl and one piece of blaze powder. You need to set aside 12, because you need up to 12 to activate the portal, and you also need a few extra eyes to find the stronghold.