i've thought about doing this too. i took a pic of my first wallaby when i was at the point that it looked like a collar. at the time, i had the thought that i wanted to make another one with a collar like this. it would be super simple. you could just use the k1p1 ribbing it already has, or you could use seed stitch, or just about anything.
married my beloved january 9, 2008!!!!! <3