Boss

A boss is a type of powerful hostile mob that displays a bossbar showing its health while alive. There are two boss mobs, the ender dragon and the wither.

The ender dragon spawns 1 second (20 ticks) after first entering the End, after which its boss bar displays at the top of the screen when in close enough proximity, and the song Boss begins playing. At the center of the island, the exit portal can be found in an inactive state. Ten End spikes surround the fountain on the outer edges of the island, on top of which sit ten End crystals, two of which are encased in iron bars. The ender dragon heals when in close enough proximity to one of these crystals, with a white beam connecting from the End crystal to the ender dragon when it is actively healing.

The ender dragon itself has 200HP × 100. It also reduces all incoming damage to it by ~75% unless the attack is hitting its head, giving it an effective 800HP × 400 if no attacks are dealt against its head. In Java Edition, due to a bug, the ender dragon's head has the same damage reduction as the rest of its hitboxes, giving no benefit to attacking its head.[1] The ender dragon is immune to critical hits and all status effects.