Stalag 666 is a comic strip by Tony Lee (his first) and Jon Davis-Hunt which was published in 2000 AD progs 1600 to 1614. The story drew a number of negative reviews, which progressed to actual hate mail and to writer Tony Lee being sent human excrement in the post (though the sender, clearly not a genius by any standards, actually sent the offending material to the wrong address, deeply upsetting the members of Lee's family who were living there). The strip has never returned, but Lee continues to write for both 2000 AD and the Judge Dredd Megazine, justly undaunted.
A stalag is a German P.O.W. camp, from the German Stamm base and Lager camp. (Source: Chambers Dictionary, 10th edition.)