I'd suggest going to Ravelry.com. You have to sign up but it's free to join. Input slouchy beanie in the pattern search box. You'll see a bunch of pictures for patterns come up. On the left, you can narrow your results. Only knitting, only free patterns, only using bulky yarn, for a child or adult, input the needle size you want to use. This will give you patterns with your conditions. Do follow the needle size recommendation on the yarn wrapper. It's a pain to knit bulky yarn with needles that are too small.