These unseen creatures inhabit the flooded sections of the Prison. You cannot see them, but their presence is indicated by splashes, ripples in the water, and unsettling sounds. Strategy: The key is to avoid making noise in the water. Move slowly and deliberately. If you hear splashes nearby, immediately find solid ground (crates, ledges, dry pathways) and stand still. They will eventually pass. If you must cross water, try to find ways to drain it or create temporary bridges. Running through water is a guaranteed way to attract their attention and lead to a swift death.
