This one might look complicated, but it's pretty simple to put together. Plus, some of the parts -- hood and tail -- are completely optional.
What you'll need to get started:
Put your shirt together following your pattern's instructions. This one calls for black ribbon to be sewed on the front, but really, you can get the same effect with a black marker and a lot less trouble.
For the shell, cut out two ovals from the brown fleece, one larger and one smaller. Sew the smaller onto the larger, and leave an opening for the stuffing. Fill the shell, sew the opening closed, and glue the strip of beige fleece around the edge. Stitch or glue the shell onto the back of the shirt, and that's it for the basic costume!
You can also make a tail to go along with it, if you're interested. For the tail, use the fleece or cotton you used for the shirt. Cut out two long triangles, and stitch them right sides together--or, in other words, inside out--leaving an opening big enough for you to turn the fabric right-side out. Turn it, then stuff the tail with cotton stuffing, and stitch the opening closed. For the swirl, roll the end of the tail up and stitch it to the long part of the tail. (How high up you roll and stitch determines how curly it will be). Then, attach the base of the tail to the inside of the shirt.