Minecraft wiki entry for Nether_survival, associated text: Ghasts are one of the hardest and most annoying mobs to fight in Minecraft, mainly because of their floating ability and their long-ranged fireball, which does considerable damage to both players and the landscape. If you are bridge-building across a lava sea, they might shoot you off. (One direct hit can kill an unarmored player.) That said, they do have several weaknesses: