Back when I played Magic, I would regularly clear off the card face and add custom artwork. One such card was this copy of Terror. The card is a kill spell: "Destroy target nonblack, nonartifact creature. It can't be regenerated." Basically, the concept is a creature so scared of everything around it that it dies. I knew exactly what I needed to make:

The scream was way too appropriate for Terror, and so I did exactly that! It wasn't difficult to do, either. Magic cards are easy to blank out, all you have to do is take a basic pink eraser to the front of the card and watch everything disappear. Once that's done, I just trace the design in pencil, and then go over it in ball point pen.

A lot of people rag on ball point pen as an art tool, but I happen to really like them. They're relatively easy to work with, they're cheap, and the ink lasts quite a while. I added this artwork at least 6 years ago, and it hasn't faded much at all. And thanks to the way that Wizards of the Coast rules on cards for tournaments, this card is tournament legal. There might be a judge that says no, but the odds are good that they won't care. I actually played this one at tournaments several times, and nobody batted an eye.