This is a very nice stamp, published by the Belgian Post office in honor of Marc Sleen at the occasion of his retirement. Sleen had been drawing his newspaper comic Nero for more than half a century, and is widely regarded as one of the grand old men of the Flemish comic. Incidentally, he’s also mentioned in the Guinness Book Of World Records for single-handedly drawing the longest-running newspaper strip (even though the Guinness web site doesn’t mention this).
i have never heard of that comic strip before i was looking for stuff about the nero computer software but this is a cool looking old comic strip