Ceres, the dwarf planet, is the largest body in the Main Belt and thus the single largest planetary body between the Mars and Jupiter orbits. Still relatively small, it possesses a surface gravity of about .029 g, which is less than Luna, but still sufficient to cause objects to drift or cling toward the surface unless sufficiently powered. Ceres also has a relatively warm max temperature in the "day" of about -38 C, though the average is more like -100 C. Most of this is often irrelevant, as a majority of the action of Ceres lies in the "Hidden Sea", the massive ocean below the 100 km mantle of ice, a region roughly 20 km deep before hitting the rocky core. The Hidden Sea has its own hazards, being under pressure of about 200 atm at it's highest level, and as strong as 2,500 atm at its depths. It's also too cold for normal transhumans under most circumstances, being about -20 C at the upper level and getting warmer from there, and also contains relatively unpleasant levels of salt, ammonia and sulfur. Generally, this means most biomorphs need to be adapted with Hydrostatic Adaptation, Improved Cold and Toxin Filter mods to survive. Total population of Ceres is documented at about 1 million.
Ceres' surface also has a very thin "atmosphere" of water and other vapor as ice works up through the crust and is sublimated by solar radiation, forming low hanging fog banks and penitente formations on the night side. This is interesting to note because the Cerean Transcrustal Authority (CTA) regulates all water trade from the Hidden Sea below the rock and ice layers, and their masters the Hidden Concern are known to harass surface operations for their cut of the profits. Because of this, a small class of red market operators exist who harvest water from the surface without long-term mining operations, using the short sight lines of the dwarf planet to avoid detection. Generally referred to as "vaporators", "sunshiners" or "niebla pirata", they are considered a nuisance both by local governance and independent operators, due to the fact that these are often desperadoes with similarities to Carbon Reaver pirates out in the Jovian Trojans. Occasionally, the more aggressive strain of these are called "Fog Men" or "Cloud Reavers" for specificity. They're common in the Gerber and Samhain Catenae, or the Niman Rupes regions.
Standard operations for this sort of outfit is mobile, usually based out of an Outsystem Hover, but also small units will use EVA Sleds or Rocket Packs. They travel quickly to fog bank formations in their immediate area, and utilize compressors or other equipment to gather the water vapor - then return to a small base station - usually little more than a Shelter Dome or Pressure Tent, where they filter the water for impurities, and place it in containers suitable for sale, which are smuggled back to a market to sell, either to someone travelling off-planet or who has contacts who will do so. Occasionally, groups grow more bold, and in order to get better take, will move to night-side formations of ice like penitentes, and cut them off and melt them using tools, or even use thermal weapons (torches or explosives) to mass melt them for storage - which also gives them a weapon should any Hidden Concern thugs come to stop their unapproved water collection.
"Fog Men" or "Cloud Reavers" are a different style of operation entirely - they are little more than claim jumpers and desperados. They typically operate how one would assume pirates and smugglers do, they locate independant water operations (the kind already paying The Hidden Concern) and attack or extort them. They steal any collected water (in liquid or ice form), then distribute it back among themselves to safely smuggle and launder it. They attack both actual "mining" operations, and transportation via Snowcralwer Utes or Hovercraft. Most of them operate in a fairly "civilized" manner, taking only the water, but others act like typical banditos, taking anything of value in an operation - and some are even known to kill and take stacks to sell to groups like Nine Lives. The "Fog Men" name comes from a tactic used to assault ice-mining operations during "daylight" hours when fog might limit visibility and many types of sensors, and utilizing "silent" weapons like Diamond Axes, Wasp Knives or Torches, and with Thermal Dampened vacsuits. "Cloud Reaver" is a name drawn from similarities to Carbon Reaver pirates who raid and claim-jump in the Jovian Trojans or elsewhere in the Main Belt.
(For stats, recommend Pirate (p. 12 NPC File), but add a weapon with a Diamond Axe or Torch, and add Thermal Dampening to their Standard Vacsuit)