Cut out similar shape with felt or flannel type fabric. Even short napped fur would not work due to the finished size. First fold edge for 1/4" hem and then sew right side in to shape the mouse body. Make very small cuts along the inside of the curve and turn rightside out.
Step 1: Give It Personality!
At this point it is up to you how creative you are willing to go. First you will put on it's face either by pen, marker or paint. Snip a piece of the fabric to experiment with before actually marking. Some fabrics allow for bleeding and you may not achieve the desired effect. You can snip bits of fabric or felt for the ears, nose and eyes if you prefer. You can even use those plastic google eyes that move available at most craft stores. I recommend Crafter's Pick The Ultimate! glue, but Aleene's is great and does not dry out on you inside the bottle as fast as the other glue does. If you do glue on pieces for effect, do not let children or pets play with it unattended due to they love putting things in their mouths and may choke on any pieces that could fall off. Thread a needle and sew through the nose area with long loops and after each loop, stitch another one tight, then loose loop, then tight and clip all the strands to the desired length. After the face simply thread your tail on a tapestry needle after knotting one end, pull it through from the inside where you want it's tail to be. You decided the length and if you wish to knot the outside end as needed. You may use any type of string, cord or yarn for the tail.
You can check out pogirlshines.me for a video puppet show of this mouse and the one I made years ago if I am not able to embed the video on instructables. Great rainy or cold day project, plus use your imagination when creating for a really fun puppet show you or your kids could put on!