First, find this geocache, and then you have to do some magic to be able to sign the logsheet. Grab the wand and say the magic phrase, "Hookus pocus!". Wave it over (and in) the hat and see if you can make the rabbit appear. If you can, you'll be rewarded and can sign the logsheet hidden within.
The contents in this geocache were crocheted by Mrs. Geo-Travelers (thus the 'Hookus' part of the cache name).