I used a 36 peg circular loom to create this hat with Malabrigo Rasta yarn I got from Luna Lola. The basic pattern is as follows:
E wrap all pegs
U wrap knit stitch cast on row
E wrap 3 then purl the next 2 for first row (however, the last three pegs on each row are purled) and consecutive 38 rows or until desired length (11 inches in this case)
Weave in ends
You can also watch this great video that explains how to do this pattern: https://youtu.be/NLx9By1n6BE.