(Alternate name: Articulated Python)
When I was little, I had a wooden snake just like this (but better). The cutouts allow it to bend. So I thought I'd print out something similar to see if it would work.
In PLA it is kinda stiff. A more flexible material would probably be better.
I made the snake short so that it would fit on a Makerbot, so it came out kinda chubby. It could actually be a little bit longer and still fit. At some point I will design and post a longer version for RapMan/Mendel sized beds. Or maybe a modular snake!
Oh and the STL has some weird stuff on the edges of the nose, but it doesn't seem to hurt anything when printing.
Dimensions: 80.2mm x 80.2mm x 11.3mm tall
(It is printed diagonally, the snake itself is around 110mm long)
EDIT (Feb 11, 2011)
I've included an alternate file, SnakeThin.STL. This version has a thinner core that should be only a single layer thick. It ends up being much more flexible. Skeinforge kept giving me trouble with the core so I scaled up the model slightly.
SnakeThin dimensions: 84mm x 84mm x 11.7mm tall