Given unlimited copies of each of the above type of puzzle piece, create a $9\times 9$ square which features a picture of snake.
- There must be only one snake, with a head at one end and a tail at the other.
- Pieces may be rotated, but not flipped.
- A piece with one straight edge must be placed at the the square's edge.
- A piece with two straight edges must be placed at the square's corner.
- Some pieces may be used many times, some only once, others not at all.
If my calculations are correct,
the solution is essentially unique. Specifically, there are two solutions up to rotation, but the only difference between them is that the head and tail pieces are swapped.
Edit: I was wrong, this puzzle is under specified, there are at least 3 distinct solutions.