You asked for it, and I've somehow managed to deliver (thanks to Clambo at Clam's Toy Box). Here's a look at the Underworld Warriors card front. (The back is just blank cardboard, so it's not really worth showing here.)
(Remember to click the pic to see a larger view. Enjoy.)
If you'll notice, I misquoted the bulleted "action features." All the "&"s are actually "N"s. Funny.
Thanks, Clambo, for sharing such a great pic of such a great toy. Now please send the toy to me