So, what I ended up making was more Hama (Perler) bead coasters, as they are quick and easy to make, and useful too.
Up at the top we have Knuckles, Tails and Sonic, from the Sonic the Hedgehog series. For these coasters I modified sprites from Sonic & Knuckles.
At the bottom is Wario's head from the final stage of Wario Ware Inc.
I was happy with how they came out and I think they were quite happy with them too.