Worked using the butterfly stitch from the top down.

Stitches used
Ch = chain
Sl st = slip stitch
Hdc = half double crochet
Dc = double crochet
Tc = treble crochet also known as triple crochet

Gauge:
Completed butterfly, 7 sts wide x 3 rows = 2 ¼” x 1 ¼” 5.7 x 3.2 cm

Finished Measurements:
8 ½” high x 25 ¾” wide 21.6 x 65.4 cm - since it’s circular, 25 ¾” is the measurement while it is laid flat.

NOTE: I have written it out using the conventional methods, but when I made mine I used foundation hdc to start instead of chaining and chainless starting hdc instead of ch1, hdc in same st as joining and chainless starting dc instead of ch3. You can do the same if you wish.

If you want, you can add an edging to the top and bottom edges of the scarf.
To widen the scarf, repeat rows 6-9 until desired width is reached and then finish off.
To lengthen or shorten the scarf, add or subtract from the base chain by multiples of 10, keeping in mind that the number of butterflies will be more or less than what the pattern says.