The Butterfly pattern works with a wide variety of yarns. Hook size selection will vary accordingly.
The treble crochet on Row #5 is simply a normal Treble Crochet (TC) stitch inserting the hook from front to back into the indicated stitch in Row #2. The treble is worked into that 4th stitch 2 rows below, then when the yarn is pulled through the bottom part of the Treble, it encloses the two chains in Row #3 & Row #4 and creates the butterfly body. Link of the pattern is below!
Butterfly Stitch Prayer Shawl
by njSharon AND DebiAdams
Butterfly Stitch Prayer Shawl [Free Crochet Pattern] downloadable pattern is available here.