To see the finished Digestive System, click here: http://www.craftster.org/forum/index.php?topic=60206.0
Part Two is up! Go here
http://www.craftster.org/forum/index.php?topic=60493.msg576447#msg576447Part Three is here: http://www.craftster.org/forum/index.php?topic=60493.msg592664#msg592664
Part Four: http://www.craftster.org/forum/index.php?topic=60493.msg604062#msg604062
Part Five: http://www.craftster.org/forum/index.php?topic=60493.msg620875#msg620875
My plan is to post a new set of instructions and some progress photos every couple of days. I'd love to see your progress too. If you have any questions, or my instructions don't make sense, PLEASE ask me to explain. I know I need to work on my pattern-writing skills!
Part One: Materials
You will need:
1 set U.S. size 6 (4.0 mm) d.p.n.s
1 set U.S. size 8 (5.0 mm) d.p.n.s
1 set U.S. size 10.5 (6.5 mm) d.p.n.s
a tapestry needle
waste yarn for temporary cast-ons
stitch markers (or more waste yarn)
a stitch holder
polyester stuffing
Yarn (what I'm using is in parentheses)
Angry Pink: Worsted Weight, 1/2 oz. (Caron Simply Soft Brites: Papaya)
Mellow Pink: Worsted Weight, 2 oz. (Red Heart Super Saver: Rose Pink)
Shiny White: Sport Weight, 1/4 oz. (Bernat Baby Coordinates: Natural)
Yellow-Pink: Super Bulky Weight, 6 oz. (Red Heart Baby Clouds: Creamsickle)
Soft Pink: Bulky Weight, 1 oz. (Bernat Softee Chunky: Pale Antique Rose)
Burgundy: Worsted Weight, 1 oz. (Red Heart Super Saver: Burgundy)
Green: Worsted Weight, 1/4 oz. (Red Heart 4 ply: Emerald)
Here's a picture of my yarns, in the same order.

This is a great stashbusting project provided you have a lot of miscellaneous pinks. If not, I'd love to see someone make an alien digestive system with different colors of green or blue!