The OhBoy Hat by Katrin Schubert is a quick to knit beanie in brioche stitch.
There are three sizes: 15" (16.5", 18")
The pattern calls for approximately 165 (185, 210) yards of DK weight and is knit using size US 6 needles and dpns
Sample shown was knit using Tosh DK.
This pattern is available as a PDF download.