My thanks to Jimmy Tweed again for sending me more comic scans from his collection. There's some fascinating items here that I've certainly never seen before.
Above is an early appearance of Dennis the Menace gatecrashing Biffo the Bear's cover strip in 1952. We all know that Dennis eventually gained the cover slot in 1974 but back then he was just an interior strip. Considering that Dennis the Menace had only started in The Beano the year before, I'm guessing that this 1952 strip is the first time he'd appeared on the cover. A sign of his immediate popularity perhaps, and a foreshadowing of great things to come! The brilliant Dudley Watkins drew Dennis a bit bulkier than his regular artist Davy Law did, but it's a great strip all the same.
Moving on a few years and here's a 1958 cover with Dennis making another appearance! Again, artwork by Dudley Watkins who drew him closer to the traditional version this time. (Although to be fair, like most comic characters, the design of Dennis did fluctuate a bit even under Davy Law until he settled on a comfortable design.)
As a bonus item, here's a Dennis the Menace strip by Davy Law from the back cover of The Beano from late August 1955, ending with an ad for the very first Dennis the Menace Annual. (Proving that annuals have always been published several months before Christmas, although these days they come out even earlier, in July.)