Marching Bunnies . It calls for chunky yarn, but you can adapt the stitch pattern fairly easily. Of course, I think the hat would look cute just knit in a plain color too.
I also knit the chick hat in blue.
I've actually written up the patterns for both the chick and bunny hats. I call the bunny hat "Hop, Hop" because that's what my little granddaughter calls bunnies whenever she sees one. The bird is called "Cheeping Chick" after my youngest grandson. He loves baby chicks and even has a blog by that name where he posts pictures and funny comments about chicks.
The bunny hat has the chart for the knitted bunny faces, but not the pattern for the marching bunnies. As I said before, that was taken from another pattern. If you want to make that version, then you'll have to buy her pattern. The pdf for the bunny is here. The pdf for the baby chick is here. I've also posted them in the sidebar under Miscellaneous patterns.
I almost forgot to tell you that the yarn I used is Plymouth's Jeannee Worsted. This is a great cotton/acrylic yarn. It can be machine washed and dried and looks great. All of the hats I've posted here have been prewashed. The yarn gets slightly softer and there's barely any shrinkage. I love the cotton hats for the babies. The hats are sized for a newborn. The chick hat can easily be made larger by adding stitches in increments of eight, but the bunny hat would require a little more calculating if you're using the chart. If you're knitting a plain hat, then you can also upsize it like the chick.
You can knit them for your own personal use or for charity, but not commercial purposes. I hope you like them.