Slug’s toons do leave varying amounts to the imagination, don’t they, just like Peter Pan and the Wizard of Oz.
I could tell you things about Peter Pan
And the Wizard of Oz!
(There’s a dirty old man!)[indent]-- Tom Lehrer[/indent]
Just add Slug to that list.
In this thread, one of his less ambiguous cartoons is discussed (including link to the picture; NSFW). It appears that Slug is sometimes called upon to provide an alternate picture that newspaper editors can run instead if they don’t appreciate the humor.
Here’s another thread in which another user makes the same observation. At Post #4, Da Boss Hisself notes:
Here, we have The Slug Signorino FAQ, with all the information you’re allowed to know about Slug.
Here, we have a compendium of Slug Art, with a lede pic apparently showing a self-portrait of Slug himself at work.