The first stitch is a single herringbone and then filled in the curve with closed herringbone making bigger stitches on the outside curve. I suggest you draw the shape/curve you want onto the fabric. It is quick and easy to do and can be used 'as is' or a
Butterfly chain stitch is a decorative stitch generally used in crazy quilting. Firstly make a row of straight stitches and then with a contrasting thread make a loop and bundle of the straight stitches together.