Fog/Mist AS a Block

My suggestion for the wild update is fog. It's a block that you can walk through (and if you do, slow down), pick it up with buckets like powder, or just replace it with a block. Monsters see the player from further away when the player is in the fog. The fog is a block that naturally spawns over water from swamps, mangroves, and rivers when the chunk loads for the first time. In this state only the player can remove it. But if the block appears in the event "foggy night" and "foggy day", then it will appears in greater ammounts also over Land but will disappears after a while. If the player is in the fog, he gets less visibility, which can be increased a bit with light sources and light falling through the fog becomes weaker with each block.