Back in 2014 my home D&D game (Adventures in Remlia) had taken some pretty ridiculous twists and turns.
To make a long story short, my players had discovered a giant bio-mechanical robot imprisoned beneath the earth. I've been a giant mecha most of my life and wanted to see what that ran like in D&D, so I'd essentially given my players a Megazord that needed a pilot for each limb.
Here's the very rough sketch + rules I'd made for it.
It's very Big-O meets Escaflowne.
One thing I came up with to help with maintenance and things when players were away was that the giant robot had a small team of modrons within it that helped keep it running. These little guys would scurry around the insides of this 700 foot tall mecha, keeping it going.
Since my game used a lot of miniatures, I needed modrons fast.
This is what I came up with in a hurry.
Small chunks of styrofoam, bent paper clips, googly eyes of different sizes, some sharpie faces, all hot glued to bristol board backed metal washers for bases. About 10 minutes of work and less than five dollars of materials.
They might not have lasted long, but they got laughs and 'awws' from my players in equal measure. Ultimately that's my biggest goal as a GM, so mission accomplished!