I really do love these crossover covers. I have seen these and a few other variants a while back, but the Lovecraft ones always seem to be the best (bias - granted I am a fan anyhow).
Yeah I've never seen these either, I love that Comic art is finally starting to be accepted, as "Real" art. I was a Tin Tin nut as a kid. I lived in a small town with a good library, they had a ton of old tin tin comics, and I checked them out as often as was allowed. It's cool seeing the books I loved as a child, twisted with the novels I loved as a teenager.
Here are a couple more in the vein, though not as nice as the Groat pieces. (sorry for the massive pics). Tintin mashups with some classic sci-fi by Dan Hipp: An extensive archive of Tintin/Hergé inspired crossovers can be found here.
I would pay so much money to get the Lovecraft inspired ones. Those are honestly some of the best crossovers I've ever seen.
