Minecraft wiki entry for Defeating_the_ender_dragon, associated text: If you are playing on Java Edition, it is strongly advised that you press F3 + B as soon as you enter the End, which shows the hitboxes of the endermen and the ender dragon. Because the background color of the End is dark, it can be hard to distinguish endermen from the background, thus the white-colored hitboxes can help you avoid accidentally looking at them. The dragon's hitboxes are also shown, which can help you determine the areas where the dragon can be damaged.