Calamity Mod Wiki
Boss Health Bar
  • Boss Health Bar.png
    An example of a boss health bar mid-fight.

The Calamity Mod adds a boss health bar to the player's interface that can be toggled via Configuration options.


  • Appears in the lower right corner of the screen when either a boss or mini boss is summoned.
    • Bosses with multiple parts (e.g. Moon Lord) are factored in and have their own separate bars.
    • Also appears when certain rare vanilla enemies (e.g. Biome Mimics) appear.
    • The boss health bar does not show for Sulphurous Sea or Abyss mini bosses.
  • Has a health percentage gauge, a yellow health bar, and a decorative blue bar separating them.
    • The health bar turns red as the enemy takes damage, with the red disappearing if the enemy hasn't taken damage for 0.5 seconds. This is to indicate recent "combo" damage.
  • Small text to the lower right of the bar displays the enemy's total and current health.
    • Bosses with a high amount of parts, such as Eater of Worlds' segments, have their remaining number of parts displayed with the small text instead of health.
    • Small text can also be toggled via Configuration options.
  • When opening the inventory or during Events and invasions, the bar adjusts to the left to make room for the armor and accessories tab or event progress meter.
  • When a boss is enraged, the health bar will glow red.


  • The boss health bar also works with bosses from other Terraria mods, though it may not work as intended.
  • The boss health bar will not appear with any NPC with 800 life or less.


  • The design is based on the health bars from Metal Gear Rising: Revengeance.
  • The boss health bar was co-coded by mod creator Fabsol/MountainDrew and programmer Boffin.
  • The Devourer of Gods' final form's health was intentionally displayed as 600% in previous versions of the mod, alluding to its increased armor and health.