I found a pattern that was apparently published in the magasince Knit.1, Winter 2006/07. From the comments by people knitting it the pattern seems difficult to follow with some errors in it (and it looks as if it's knitted in the round)
My favourite organ: http://www.knitty.com/ISSUEwinter04/PATTwomb.html
(uterus) Not anatomically correct, but cute. It's knitted in the round but it's not a very hard pattern to knit.
I think you should give dpns a try. They aren't as scary as it looks. It is possible to freeform patterns when knitting in the round even if it's not as straight forward as with crochet.
Most patterns like this will probably be in the round, and while you can modify them for knitting flat it's probably more of a headache than to learn to master the double pointed needles.
EDIT: Could this be something? http://www.theanticraft.com/archive/samhain05/curseyourbf.htm
It's just colourwork and not 3d so it should be simple enough.