Boss Masks are vanity items dropped by most bosses added in the Calamity Mod. They are worn in the social head slot, like vanilla masks. Each boss has a 10% chance to drop its own mask. In total, there are 14 boss masks.
- Unlike most masks, the Hive Mind's mask looks different when equipped on the player than when viewed in the inventory.
- The mask for Providence represents a former sprite for the boss, and has yet to be updated for her new appearance.
- There are many bosses in the mod which do not have masks, and are as follows: Brimstone Elemental, Aquatic Scourge, Ravager, the Profaned Guardians, all of the Sentinels of the Devourer, Polterghast, Bumblebirb, and Supreme Calamitas.