Based on the droids seen in the Clone Wars cartoons.
About this creation
So I was watching the short little Clone Wars cartoons, and a whole bunch of these were attacking something or other. Don't remember much now, but what I do remember is that these droids were all tan in color. I'd had just recently gotten the two big sphere halves from the Johnny Thunder Hot Air Balloon set and I knew they would be a perfect size for the main body of the droid.