Calamity Mod Wiki
Flak Crab
EnvironmentAcid Rain
AI TypeFlak Crab AI
DamageContact: 0
Flak Shot: 46 / 72 (Tier 2)
Flak Shot: 84 / 128 (Tier 3)
Max Life300 / 600 (Tier 2)
4,125 / 8,250 (Tier 3)
Defense999999 (disguised)
20 (moving)
DR20% (Tier 3)
KB Resist100% (Disguised)
80% (Moving)
40% (Jumping)
Inflicts debuffIrradiatedIrradiated
100% chance
Debuff duration2 seconds (Flak Shot)
Debuff tooltipYour skin is burning off
Immune toConfusedKami FluIrradiatedSulphuric Poisoning
BannerFlak Crab BannerFlak Crab Banner

The Flak Crab is a Hardmode enemy that spawns during tiers 2 and 3 of the Acid Rain event. They disguise themselves as a geyser and will move around after taking damage. When disguised, it will shoot Flak Shots, which will inflict the Irradiated debuff.


  • The enemy itself does not have any contact damage, only the Flak Shot damages the player.


  • This enemy is a reference to the Hermit Crab enemy from Risk of Rain 2.
  • The way Flak Crabs attack is a reference to the Aeroflak Cannon from Robocraft.
  • The Flak Crab's disguised state is tied with the Devil Fish's masked state for having the highest defense of any enemy in the mod.

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