Slime Glutton
You are a slime. You cannot attack. All you can do is touch things and swallow them.A mob smaller than you can be swallowed. Touch a bigger one and it swallows you instead, and the run is over.The same mob is food or a threat depending on your size. Swallow 500 to clear.The bigger you get, the heavier you move.Dig up chests along the way and fill the gem collection.