How exciting! I see you did a clay model first. Looks like you patterned some of that perhaps but also did some block foam build up that was sculpted.
I usually use the clay models to pull the pattern. The image here was from after the pattern was made and I fixed the model to use as a reference.
For this process I sculpt the clay model and cover it with a layer of newspaper coated in wallpaper paste. When it dries I mark out the cut lines with a black marker (like a sharpie). Then cut out the pattern with a sharp utility knife, pull the sections off and transfer to paper. The paper pattern is transferred to foam sheet and the pieces are holtmelted together.
Now the hard part starts...getting the mouth and eyes to work right!

Shunaka