When my sister-in-law called wondering how she was going to pull off an Agent P costume for her 3 year old, the gears started turning in my head and I couldn't NOT do it.
It turned out the way I imagined it, which is always very satisfying.
For the webbed feet, beaver tail and duck bill I used double layers of felt. With the tail I added a layer of batting between and quilted the cross-hatching into it to give it some dimension and texture. Between the felt layers on the bill I hand-stitched two bits of pipe cleaners to help bend the bill into a curved shape. They're all separate pieces, with elastic to fit around his ankles, waist and around his face.
They already had the hat. PHEW.
I had imagined myself making a detailed tutorial for each piece, but then I just wanted to get it done. ;)