Block Monsters!

If you have been troubled by the thought of your monster friends rolling away, then these are the creatures for you! Block monsters
from Little Fluff Stuff are Guaranteed not to roll anywhere! I checked the fine print and it's true! I noticed that it didn't say anything about hopping though, so you may still want to keep them in a confined space. I've had a bit of experience with monsters, and they look like hoppers to me...