|Spawns In:||The Mines|
|Variations:||Rock Crab, Lava Crab|
They disguise themselves as stones, sometimes surprising the player. When immobile, they are invulnerable to attack, though you can hit them with your pickaxe to knock them back, making them mobile again.
To identify the Rock Crab, you have to look out for rocks without shadows, sometimes slightly overlapping nearby rocks, as well as rocks on dirt patches (not including Nodes).
The Rock Crab can only be dealt damage if it is mobile, and not hiding beneath its rock. You can strike an immobile Rock Crab with your pickaxe to make it mobile again. Striking a Rock Crab with a pickaxe enough times will knock the rock off of the Rock Crab's back, and will cause it to flee. Alternatively, setting off a bomb near a Rock Crab can remove its rock, and will cause it to flee as well.
- 1.0: Introduced.
Glitches: If the rock crab is standing in the middle of a 2x2 area next to a wall;if you hit it with a pickaxe when its rock has already been broken,you will instead hit and break an imaginary rock that isn't there instead of hitting the monster.
|Mines||Bats • Bug • Cave Fly • Duggy • Dust Sprite • Ghost • Grub • Lava Crab • Metal Head • Rock Crab • Shadow Brute • Shadow Shaman • Skeleton • Slimes • Squid Kid • Stone Golem|
|Skull Cavern||Armored Bug • Big Slime • Mummy • Serpent|
|Bug Lair||Mutant Fly • Mutant Grub|