Boss Bloons are the biggest single entities in Bloons TD 6: MOAB-class monsters with health bars that span an entire event, fought in special Boss Events rather than normal play. Seven exist, they rotate weekly, and each one fights differently enough that the community treats them as seven separate disciplines.
The seven Boss Bloons
- Bloonarius the Inflator: the first boss, introduced with the v27.0 event system, a spawning swamp titan.
- Gravelord Lych: the necromancer boss, notorious for feeding on your own buffs.
- Vortex: Deadly Master of Air: the speed boss that punishes slow, static defenses.
- Dreadbloon: Armored Behemoth: the rock boss with layered armor phases.
- Reality Warper Phayze: the teleporting boss that bends the track's rules.
- Blastapopoulos: Demon of the Core: the magma boss with area denial.
- Diamondback: added to the rotation in the v54.x window, the newest permanent boss.
How Boss Events work
- A boss event runs for about a week on a specific map, and the boss appears in escalating tiers, each with more health and nastier supporting rounds.
- New bosses debut outside the rotation before joining the weekly cycle.
- Co-op boss fights arrived in v28.0, and Ranked Bosses time your full clear of every tier for leaderboards.
- A separate Boss Challenge mode lets you fight any available boss under standard rules (see modes) at any time.
- One save detail matters: Boss Event progress has been locked to the device that started it since v33.0. Switching devices mid-event forfeits the run; this is the most common troubleshooting confusion in the format.
How scoring works, briefly
Score is generated by the damage and tiers you achieve against the boss during the event, and submitting that score is automatic when you finish a boss run in the event screen. If the event UI is confusing, the short version is: enter the event from the Events tab (see all event formats), beat tiers, and the leaderboard records it. There is no separate submission step.
⚠️ Unconfirmed. Exact tier rewards, boss HP values and leaderboard tiebreakers are version-dependent and not officially documented. We describe structure, not numbers, on purpose.
FAQ
How do I submit a score in a Boss Event?
You do not submit anything manually. Completing a boss tier during the event records your result on the event leaderboard automatically. If your result is missing, it is usually a save-device mismatch: the event only counts the device where the save lives.
Which boss is the hardest?
Community consensus shifts with every balance patch, and "hardest" depends on your towers and Hero. We do not rank bosses, because the ranking would need a version label that goes stale.
Can I fight bosses in co-op?
Yes, co-op boss fights have existed since v28.0, and they are one of the best uses of the 4-player support.