you need one
The Word Detective : CafePress.com
Yes, it's the Official TWD Hat, sporting the Official TWD Motto, available in tan (shown) or white. Click picture for larger view. Available at the link above, along with scads of other groovy TWD swag.
p.s. -- If you have to ask, you're not allowed to buy one.
p.p.s. -- Just kidding.