2 versions of the same hat, one slightly slouchy and one very slouchy.

A simple slip stitch pattern is used for the body of this hat worked in the round; easy to memorize and great for variegated yarns. The very slouchy hat is fuller and longer.
Included in the pattern are photos, a complete list of abbreviations, and a stitch glossary.
Skill level: Advanced beginner.
Experience with working in the round helpful.
This hat is worked from the bottom up.

Any DK weight yarn can be used as long as you match gauge. Yarns of different fiber content and twist will give a slightly different look. Any variegated or handspun yarns would be fine. For an even slouchier version use a drapey yarn, one with some silk or bamboo, or a single ply yarn.
The slightly slouchy version uses about 200yds and the very slouchy version uses about 250yds.

I also have a paid for pattern that features this design written for 7 different weights of yarn, Lucky 7.