Created for me by Tempestryder @ FA.

Name:
Crab Mover
Class:
Universal Carrier / Constructor robot
Role:
Primarily: Excavator and Lorry
Origin:
Generic Template - common to all Asgard Habitats.
The design is modified as needed, thus all measures given here are for the default model.
Size:
Torso 3 m tall, 8 m wide, 8 m long
Weight:
22 metric tons
Power:
Fuelcell for travel and emergencies
Beta decay nuclear battery for memory core and beacon
Cabled power at construction sites

Mobility System:
On smooth surfaces, the Crab lowers itself down onto the roadwheels that form its legs upper tighs, allowing it high speeds.
On rough terrain the legs are used to walk.
Each leg-tip can unfold four claws to hold or manipulate objects - intened to hold on to surfaces in zero gravity or work overhead in low gravity environments.
Additionally the claws can be magnetized to allow the Crab to move over metallic surfaces without slipping.
If needed, the utility arms assist in moving around.

Work System:
There are two utility arms that can equip a wide range of tools. These tools are stored under the forward caraprace, which opens for this.
Rear section is cargo compartment, 5m x 4m x 2m, modular, rests on the legs mounting point platform.
To fill its cargo compartment, the arms expand further from under the carapace to allow motion along an additional joint not visible in this picture. The excavated material is then poured into the cargo compartment through the upper hatch.

Control System:
Better than IBM's Watson in 2019, there is limited purpose AI, or a high level expert system. A crab is not self aware, but can analyze a problem to a high degree and in an emergency act on its own decision. Crabs can command Trilobites, of which they carry two under their carapace for self maintenance together with an array of Octopi.
Crabs understand sapient communication in regards to instructions pertaining to their task and to most common emergencies. Most Habitat ACs give them deep, slow voices sounding like steelplates and gravel.

Notes:
Pacifica AC has a range of tiny Crabs, just as big as a Trilobite Builder, which stay always near the beaches as a sort of coast-guard. Several of those can be seen recreating sandcastles children built before, and often increasing these castles complexities or sizes. Why they do it nobody knows. But as people enjoy watching them on rainy days cooperatively building entire sand-fortresses, it is most likely a quirk that will remain.