rwcarter
The Chariot and Devil cards are icons in the bonus round of the Mystery Fortune slot machine game of the Slot City app on the iOS. (Don't know if there are versions for other PDAs.)
the Happy Squirrel card is a notable example since, unless the broad public has a basic grasp of what tarot is and does, the joke wouldn't work at all.
Not sure if it is still available to purchase, but many years ago, I bought my husband a Tenacious D tee shirt that featured the RWS Devil card, with the slaves having been replaced by Jack Black and Kyle Gass (the members of Tenacious D). He still has the tee shirt, it's really a good chuckle.
eta~just had a look around the web, and while there are loads of Tenacious D tee shirts available, that one no longer exists. I wonder if they ran into some kind of copyright issues.
That sounded really familiar, so I had to check, here is how it looks.
http://tshirtslayer.com/files-tshirt/styles/shirtview/public/user-832/DSCF2197.JPG?itok=eX7gBvUR
Found it on Google Images, and I think it might be available from other sources as a bootleg