 The DM could show the monster's picture to the players, while keeping the statistics hidden.The "Monster Cards" Sets 1 through 4 were designed by the TSR Design Staff, with art by Jeff Dee, Erol Otus, Jim Roslof, Darlene Pekul, and Bill Willingham, and were published by TSR in 1981 as sets of 20 color cards in a small clear plastic box.Additional contributing artists included Jim Holloway, Harry Quinn, Steve Sullivan, and Dave LaForce.