I remember seeing that pattern a few years ago in a book. It had green turtles on it, and the head and tail had a triangular shape. I will look through some of my books tonight.
Google turtle quilt patterns and some will come up. I am sure you can find a pattern there.
https://www.pinterest.com/mlisscreates/quilt-turtle/ about 1/2 down there is a pattern showing the breakdown of the pattern
Here is a quiltville one, although the pattern is not there, you can wing it:
http://quiltville.blogspot.com/2012/...scrap-bag.html