#include <std-disclaimer-forum-post-about-other-peoples-typos.h>
Nobody mentioned the 'sneak preview' Billy Whizz yet? Several Beanos ago, a Billy strip was printed on top of the one which would go on to be published the following week. Not all the panels had borders or backgrounds, meaning in some of the transparent holes there was more of the mistake strip than the actual picture. Very confusing. I'll scan it later if nobody beats me to it.
And, OK, so this isn't really glaring, and in fact it's sadly par for the cause in today's typo-riddled Beano, but just for the record, in the penultimate panel of this week's Gnasher's Bit(e) Dad says, "Sigh. I'm here to collect Gnahser."
Text escaping from speech balloons always used to be quite commonplace, but it's been more or less superseded by different types of errors recently. The most common mistake, back when the Beano had only just switched to digital lettering, used to be text present on the page without the balloon around it. This was inherently very difficult to spot, so there were probably more examples than those I remember.
And I can't believe everybody's forgotten this one:
Roger the Doger, two weeks running. Same issues as the two which were mistakenly numbered as #3577, incidentally.
And then there's loads more other stuff of decreasing significance. There was Super School's scattergun colouring, where Invisible Isobel's non-specific 'inclusive' ethnicity trotted around almost every colour on the globe, and Bananagirl's yellow banana-shaped hair, which turned brown every other issue (presumably it had gone off), to name just two examples. Non-white skin was, rather embarrassingly, a particular blind spot of the Beano for some years - watch out for supposedly black characters wearing shorts which reveal their white knees, and background characters who were drawn black but coloured white; Barrie Appleby's later (2007-ish to 2011) Roger the Dodgers are a good place to go for both, and for both simultaneously in a convenient place, look at the 2011 Beano annual, Ball Boy strip, page 2, panel 5.
The Beano contents page used to have a mistake almost every other week, which is probably behind its recent wise move from page 2 to page 3 (which is printed later).
And finally, although it isn't a comic, the subscription adverts (yes, that page which you always studiously ignore - they're
surprisingly enlightening when you pay attention!) in issues #3595, #3596 and #3597 (yes, three weeks in a row), which were dated 23rd July, 30th July, and 6th August respectively, had been accidentally copied from a much earlier issue, and advertised an offer which had recently been superseded by personalised merchandise, with expiry dates in the small print given as "11 June 2011". (This is the worst, but not the only, example of a sub ad fail in the year of 2011 - read the linked post for more!)