Kaiser Crab is a boss in Slay the Spire 2. Here is what she or he does, the moves to expect, and the order that actually wins.
A two-target fight against the Crusher claw (199 HP) and the Rocket claw (189 HP). Destroy both claws and the body flees.
The fight at a glance
| Act | Act 2 |
| Location | Hive |
| Difficulty | Hard |
| HP | 199 + 189 |
| Key mechanic | Dual Claws / Positioning |
The rotation
Both claws attack simultaneously every turn. Crusher alternates between attacks and Block buildup. Rocket escalates from light multi-hits to a devastating Nuke around turn 4. Killing one claw triggers Enrage on the other.
Moves
| Move | What it does |
|---|---|
| Crusher Strike | Crusher’s basic attack dealing ~10 damage. |
| Fortify (Crusher) | Crusher builds up Block, becoming harder to damage. |
| Rocket Barrage | Rocket’s multi-hit attack dealing ~4 damage per hit. |
| Nuke | Rocket’s heavy attack on ~turn 4 dealing massive damage (~35). |
| Enrage | Triggered when one claw dies — the survivor gains 5 Strength and 99 Block for one turn. |
How to beat Kaiser Crab
- Focus the Rocket claw first — it has lower HP and deals far more damage, especially the Nuke. AoE damage is excellent since it hits both targets. Be ready for the Enrage when the first claw dies — the 99 Block means you get a free turn to set up, but the +5 Strength makes the surviving claw dangerous. Poison and damage-over-time effects bypass the Crusher’s Block stacking.
- Kill the Rocket claw first — it’s the bigger threat with lower HP
- AoE damage hits both claws and is very efficient here
- When one claw dies, the other gets 99 Block — don’t waste attacks that turn
- Poison and direct HP loss bypass the Crusher’s Block stacking
Where to go next
The boss table lists every boss with HP and key mechanic. The deckbuilding basics page covers building for fights like this one.