This video is taken from the Frog Bowl project.
This was a tricky idea: a frog climbing out of a pond (AKA bowl), and this model helped me understand what I was taking on. The lesson included my research and drawings. However, for me, these weren't enough. To visualise the subject, I needed the three-dimensional 'playing around' that clay gives me.
I used 'NewClay', which contains glass fibre strands and dries hard without cracking. A 'normal' clay would need an armature in this leg to stop it breaking off when it dried. I buy the Newclay from Alec Tiranti's, a sculpture material supplier in the UK. I don't know of a supplier outside of the UK but a web search might find one, and here is the link the Newclay website if you want to contact them directly.