Thread:Richmond2010/@comment-4156018-20121219095201/@comment-259642-20121220123548

After Unlimited, certain bosses have this system that decides the boss's MaxHP. The following are taken into consideration: The boss's MaxHP can only be in the range of #maxHP to #finalmaxHP.
 * The amount of players participating in the fight
 * The level of the highest leveled player
 * The MaxHP of the highest leveled player
 * The Weapon/Magic attack of the highest leveled player

The boss icons are in UI.wz. There's no need to use the UI.wz for your extractor anyway, since it just needs to print the monster name in the 'icon' field. The boss icons are used if there is bgColor or something like that, there are two of them. If both are used, then the icon is taken from UI.wz. If the icon is available in the UI but the two tags, or either one of them, are not present, it is not used. If both tags are in the monster's .img, but the icon is not in the UI, there is no boss icon, but the health bar at the top of the screen is still shown.