In the order info section of the first game (or in the shareware version, I can't recall which exactly) there was a blurb about the "Official Jazz Jackrabbit T-shirt" that'll make all your friends "green with envy".
So far I haven't been able to locate a single pic of said shirt except for fanmade ones and the sprite shirt that's available for sale at
Epic Game's merch site. Did anyone here purchase one back in the day?