By the way... what is the name of the thing?
Anyway, it is a fun monster and my child love it, so...
Step 1: What We Wear
Two steel bearings.
One little magnet.
Step 2: The Eyes
The magnet should be easily hidden by the threads.
Step 3: The Results
Their only defect is that they dump easily by the weight of the bearings, so be restrained or put it a base.
I found a vein of theese balls in an old scarf, so I will make a lot of monsters with spares of toys I have lying arround, but this will remain my favorite, I'm sure!
Thanks for your time!