蛇　Hebi

The body lies flat on the ground plane.

What is fixed is not the shape but the direction of each segment.
The directions form a wave, and the position is what you get by adding that wave up.

The wave rises at the head and leaves through the tail at delayed times.
The same bend passes along the body and goes out the end.

The swing is not even. It is small at the neck and head and grows toward the tail.
So the head stays almost settled while only the tail sweeps wide.

The body is four hundred and eighty rings. Each ring is spanned by the sideways normal
and the upward binormal at the same radius.
Whichever way the body turns, it stands as a round tube and never flattens into a band.

The rings are thin at the tail, thick at the middle, and drawn in again at the neck.
The head is wider than that neck, and separates from it clearly.

The tongue comes out only for a short while. The rest of the time those six hundred points
are folded inside the head.

Reduce the points and the thickness goes first, leaving only the line of the winding.
Then that line breaks too, and what is left is the path of a single point.

While that single path moves, it is a snake. Stop it, and it is only a line.