The facility's giant semiautonomous geological mining machines, whose stored logs are Murderbot's evidence and whose bodies become its weapons.
The diggers are the terraforming facility's huge geological-manipulation machines, semiautonomous extensions of the geo systems rather than true bots, curled inert in containers three times the size of the survey shuttle beneath the geo pod. They serve Murderbot twice over. First, their onboard scan logs, dumped to their buffers but never fully deleted, are the very evidence it came for: proof that GrayCris scavenged alien remnants under cover of terraforming, which Murderbot copies into the clips hidden in its arm.
Later, with Don Abene powering up the control station, Murderbot drives three of them, sans mining protocols, as improvised weapons and diversions, walking them across the facility's exterior to menace the shuttle and cover the crew's escape, and using one to snatch and crush a combat bot at the docking port. Multi-armed, powerful, and eerie on their cameras against the storm, the diggers are the tools that both indict GrayCris and help the team survive.
Enormous multi-armed geological mining machines with gripping limbs and onboard cameras and scanners, coiled in vast containers, able to crawl over a facility's exterior and crush a combat bot.
Plot-critical equipment: source of the evidence against GrayCris and Murderbot's improvised weapons in the escape.