I saw one made by Megan at Mousehouse which I really liked so I followed her links to a tutorial. It was about 3 hrs in total to make up. Mine has smaller squares as I had just 25cm of each fabric so each square was approx 12cm. I used a cotton batting between the layers to keep it light and easy to wash. It ended up being about 75cm x60cm - good for prams, in cars or as a play mat. Don't look too closely - it's not perfect but that's what handmade is about and I am sure the boy using it won't notice.
The latest issue of Mollie Makes Magazine (here) turned up and G requested a hamster ( not that she has even seen one as we don't have these in NZ) - it's pretty tiny - about 5cm long .