The greymen

Do you notice a squad of small humanoid beings in grey suits with blue visor windows on their helmets? These are simply dubbed the greymen. Averaging in size to about the size of an adult human's thumb, they tend to come out only after the periscope has vanished. When this happens, they'll often climb up to the edge of your bedside and just stand around, with one usually holding a flag of sorts.

As such, many believe the greymen to be the ones who pilot the periscope. If spotted, the greymen will quickly dive off the bedside before one is able to swat them away. Even if you pretend not to notice them and try swatting at them, they have great reflexes and will dodge instantly, once again retreating to back under the bed. Should you leave them be though, they'll plant their flag before slowly diving back off the bedside. As such, you may keep the flag, and even display it elsewhere in your room should you so desire. However, the flag cannot be seen by others and must be kept in a special case to prevent it from despawning. As the greymen have many different flags, it's worth investing in one of these cases so that you may collect all these flags.