So you have already seen some of Dave's construction process in building Dr. Cortex. As he mentioned, part of the head was adapted from a Project Puppet pattern purchased a few years back. In all honesty, we learned an invaluable amount from those patterns - most of all, how to simplify...
When I start to think of character designs, I create a few sketches to try to capture an essence of the character. This time I am able to draw from an endless library of images online to get a feel for these exotic creatures. As I feel more comfortable, I start to really dissect the 2D design into 3D shapes.
The first decision to be made is deciding on hand placement. Every good design keeps in mind the shape and placement of the human hand for optimal manipulation. With Wally, we knew he needed to be very expressive and have the ability to communicate a variety of emotions - so we quickly realized a rigid mouthplate would not do the job. Being my first time venturing into a "soft palate" puppet, I was curious to see how different it would be and how well it would hold the supporting shape.
One of the most notable features I found with wallabies in general is a strong rostrum bridge - taking note of this I simplified it down to a simpler shape - like a "T" wearing a superhero mask.
Check back again to see how it developed as more foam was added...
PS - I can't believe how practical Math and Science are to the artistic process... Maybe I'll write more on that later.