freshwater sponges.

I think this should be added because we can't just add salmon to a lake and call it perfect which I mentioned in another post. We need more mobs in lakes. And I think a colonial animal in lakes would be the bomb! 

Freshwater sponges are colonial animals in Minecraft. They should grow in rivers and lakes.

Freshwater sponges are colored green. They spawn in lakes as a single block. They eventually get bigger. Freshwater sponges never spawn in the ocean or move. They can be used to get rid of water. They can grow in any other water body if they are placed in it even if its made by a player.