Only minimal sewing experience is needed, and in a pinch you could even substitute fabric glue without too much difference. The illustrating photos were taken with some creative use of Photo Booth, but hopefully they are clear enough to help.
You will need:
+ approx. 3' x 1' black felt
+ batting (har har) or cotton balls (I used stuffing from an unwitting pillow - you won't need more than about two handfuls)
+ needle and thread
+ scissors suitable for cutting fabric
+ scrap paper and a pencil or pen
+ ribbon (about 3 yards)
+ seed beads (I used 6 pairs in different colors, so 2 red, 2 yellow, 2 blue...)
+ an embroidery hoop (I used a 12" from a thrift store)
+ little bells, if you want them (I used 6 that were about 1/4" in diameter)
+ spray paint OR smallish paintbrush and acrylic paint in the color of your choice (you will use these to paint the wooden hoop)
+ small ring (key ring, carabiner, wooden napkin ring, etc., from which the mobile will hang)
This is my first Instructable, so if it is unclear in spots, please let me know and I'll do my best to clarify.
Step 1: Making the pattern
Cut it out halfway, then fold it in half to make sure it will be roughly mirrored on the other side. I had to adjust the ears and the tips of the wings on mine. Then finish cutting out the bat.
This cutout is your pattern.
Step 2: Cutting your bats
Place your pattern on the black felt, and trace around it with the chalk. Repeat until you have 12 bat outlines. Then cut them all out. It will probably take a while.
Step 3: Preparing to assemble bats
First, take your twelve bats and pair them up so that they each have a partner that basically matches. I am an impatient cutter, so my bat outlines were somewhat eccentric. By pairing them up now, you make sure that you don't end up with two bats at the end that look mismatched.
Then, cut three yard-long lengths of ribbon and set them aside.
Step 4: Bat construction!
The instructions here vary depending on whether you are sewing or using glue. I sewed, but gluing would actually be a lot easier. The downside is that I don't think you could stuff the bats if the seams aren't stitched. Here's a rundown of what should happen in this step.
First: Attach the eyes. Glue them on, or sew the seed beads onto the "face" of one half of your bat. Don't cut the thread - keep it long so you can use it to sew your bat's outline.
Second: Close the body of the bat. I wanted to keep the pairs' wings separate so that they would fan out more and look more... flappy... so I only stitched around the middle of the bats, attaching their heads and bodies, and left the wings and ears alone. Leave the top of the bat open, but don't cut the thread yet.
Third: Stuff the bat. Take a little of the batting and push it inside the bat's body through the head so your bat gets all puffy and fat. Push in a little more until it seems full enough. Make sure it isn't poking out the open end.
Fourth: Attach the ribbon. Take the end of one of your ribbons, push it under the batting, and sew the bat closed, making sure your needle and thread pierce the ribbon at least two or three times so that it won't pull out, even if a baby is whacking at it.
Fifth: Sew or glue a jingly bell to each bat's tail.
LOOK HOW CUTE YOUR BAT HAS BECOME. I took several pictures, as the detail isn't very good, so you can see it from many angles. If you decide to glue instead of sew, just make sure you get the ribbon glued in when you seal the edges. I wouldn't attempt to stuff it.
Note: You will end up with six bats (duh). There will be one attached to each end of your three lengths of ribbon. Make sure that the ribbon doesn't get flipped - you want to be able to lay the ribbon flat and have both bats face the same way, eyes up or eyes down.
Put all six bats together this way, and then move on.
Step 5: Painting the hoop
It can be tricky to get more paint on the hoop than on your hands, so you should probably do one surface at a time. If you, like me, are impatient and would rather paint all exposed surfaces at once, you may want to employ a set of "helping hands" to clamp the metal screw and allow freer access to all four sides of the wood. You should still expect to get paint all over you, and should probably apply more than one coat.
Spray paint may be a simpler option. Try that, if you'd rather.
Step 6: Hanging the bats
Use a measuring tape and pencil to lightly mark where each bat should hang. If you don't have a measuring tape, use a ruler to mark a piece of ribbon or paper to the correct length, and wrap that around the hoop for measuring instead.
Attach the ribbons to the hanging-ring. I looped them over and through so they'd stay on well, but you could just pass one from each pair of bats through and have them hang loosely if you wanted.
Then determine how low you want each bat to hang. I like to give them each about 8" of swing. Mark approximately even heights up the ribbon on each bat using pencil, and then put a small piece of masking tape (thinner than the embroidery hoop) right at the mark.
Open the embroidery hoop. Tape the bats in place, on the inside hoop, facing outward. Then carefully slide the outside back on and tighten it in place.
You have completed your patented plushy bat-mobile! Go make some wee beastie happy.