It looked easy enough to reconstruct so that is what I did.
3 embroidery hoops, various sizes
black acrylic paint
black embroidery thread
large hand sewing needle
black cardstock or felt (stiff felt preferred)
First Step was taking the inside hoops and painting them black
Next I cut out about 31 bats. I used black cardstock because I can cut 4 at a time versus one at a time with felt. Since this was an experiment, I didn't want to invest too much extra time. I just created my own bat stencil/template but if you'd like to use it, just email me at firstname.lastname@example.org and I'll send it to you.
Then I tied strips of the black embroidery thread approx 9" long around the hoop eyeballing them about 2 and 1/2 to 3" apart like this: After all the strings were attached, I took tacky glue and applied a little to the ends to make it stiff and much easier to thread. Then I put a small amount on each knot (around the embroidery hoop) to make it more secure.
To add the bats and pom poms, I threaded each strand (one at a time) on a needle and then I strung the bat and two pom poms. I tied a thick knot at the bottom so they wouldn't slide off over time and trimmed any excess. You can really play with the length of each strand to get the effect you want.