Place the catnip in the square of black gauze and sew into a little bag. Place the bag into the bottom of the spider 'body' filling the remainder of the cavity with scraps of black fabric.
To make the legs, crochet 15 stitches and single crochet into the second from the end and back to the beginning (13 st). Fasten off and repeat 7 more times.
Fasten the legs to the body of the spider, and using thick white thread, embroider a smile and eyes onto the face.