Born to be a guerrilla unit, the Crab is a heavily armed and armored medium 'mech know for its logistical durability. It has a maximum speed of 86.4kph that allows it to avoid most heavy and assault 'Mechs but leaves it vulnerable to machines of it's own weight class. The Crab also suffers from an extremely steep heat curve. The Crab has sufficient standard heat sinks to facilitate repeating firings of its twin heavy lasers. Adding its supplemental weapons, a medium and small laser, quickly overheats the machine. Designed during the last days of the Star League, the 'Mech proved a superior unit before being forgotten during the Succession Wars.
The Crab carries two arm mounted RamTech 1200 Large Lasers which are backed up by a Ceres Arms Medium Laser and a Exostar Small Laser. While this is a high heat design the all laser configuration does lend itself to guerilla warfare.
- CRB-30 - The CRB-30 is a complete rework of the CRB-27 Crab. To start the standard engine has been replaced with an XL model. The CRB-30 puts this new extra free weight to good use by replacing the twin Large Lasers with a pair of ER PPC's and upgrading the Medium and Small Lasers to ER models. The standard Heat Sinks have all been replaced with Double Heat Sinks. The last part of this upgrade is the addition of a Guardian ECM Suite and an improved c3 computer.