Hi we have volunteers that knit toy mice for us and we fill it with catnip (which proves very popular, my cats have left theirs very soggy!). I've copied the pattern below.
CATNIP MOUSE KNITTING PATTERN
MATERIALS: Use double knit or similar yarn, anything thinner will be torn apart too easily, much thicker will be too stiff. Two different colours, one for main body and contrast for nose. Nice bright colours, please – the cats don’t care, but the customers do! Size 2.75mm/10 needles (use 3mm/11 needles if end result is too small). Standard abbreviations used.
TENSION: Ideal length approx. 5”/12.5cm, width approx. 5”/12.5cm at widest point. Stitches should be fairly tightly worked. Work in stocking stitch throughout.
BODY: Cast on 9 sts. for tail end of body.
Row 1: Increase in every stitch knitwise. (18)
Row 2: Purl.
Row 3: (k1, incr. in next stitch) to end. (27)
Work 3 rows.
Row 7: (k2, incr. in next stitch) to end. (36)
Work 11 rows.
Row 19: (k2, k2tog.) to end. (27)
Work 9 rows.
Row 29: (k1, k2tog.) to end. (18)
Work 7 rows.
Row 37: (k2tog.) to end. (9)
Work 3 rows.
Leave approx. 12“ of main colour for sewing
Last row – using contrast colour for nose – knit.
Draw yarn through loosely, leaving approx. 12-15 inches for eye embroidery.
EARS: (make 2 in either main or contrast colour)
Cast on 18 stitches, work 2 rows.
Last row: (k2tog.) to end (9).
Draw yarn through loosely, leaving approx. 5-6 inches for sewing.