A year or so ago someone at Dr Pepper came up with the new slogan of "Always One of a Kind." Soon thereafter the slogan was applied not only to the King of Beverages, but to the Peppers who consume it.
Once this caught on, someone at Dr Pepper (the same person, for all I know) decided it would be a good idea to sell customizable shirts making use of the slogan. The classic Dr Pepper-maroon shirts carry the logo and slogan on the right sleeve and allow you to complete the "I'm a ..." with words of your choosing.
A friend was kind enough to send one to me with the slogan, "I'm a Hawaiian at heart":
I'll wear it with much aloha.