The CRB-S are giant robot dogs, quite a bit larger than their cyberdog cousins. Designed for non-lethal (in theory) containment of Denver's revolting population, three of these units were in use by the Denver City police department prior to the deployment of the National Guard.
One of Dog Town's quests is to get rid of these three robots, as they would continue to harass the player. An alternative is to reprogram one of them to follow the player as a companion (but only within Denver city limits) or to change the priorities of the robots and use them to drive out the dogs roaming the city, salvagers, Caesar's legionaries, etc.
It also had the Bonus Move perk, giving it 2 extra movement AP's. Other than the skills listed on the right, it also had Van Buren-specific skills, namely Programs = 50%, Electronics = 25%, Mechanics = 80%. Its starting XP score was 1111.
CRB-S have not appeared nor are they mentioned in any published game. They were to appear only in Van Buren, the canceled Fallout 3 by Black Isle Studios. It is not certain if they will appear in any future Fallout game.