This is the next iteration of my Slinky Snake that's cleaner and prints even faster - 1 hour and 40 min. for the body. It also can stretch out to more than 1 meter. This is designed to be printed on end, which is both much faster and much stronger than printing it flat. Tree supports are used in the 3MF file provided to form a cradle to hold the tail  securely for printing (see last photo). THe supports break away cleanly after printing.

 I've provided 2 versions: one with a separate body and eyes that can be printed in contrasting colors (just press or glue the eyes in place), and a single piece version.

Post Printing

DO NOT just try to yank the coils apart after printing - the coils are easy to kink. First, remove the tree support base - it should break free pretty easily, but you can use cutters if necessary to help break it away. 

Then, to free up the spring, gently poke a thin blade, like a pocket knife or xacto knife into the gap between the coils and then then work the blade along the entire length of the coil to free it up. I actually used the back side of an xacto knife blade rather than the sharp edge, wiggling it a little as I went to break the coils free.