The two "Witch guard' goblins, Mudd & Tubbs, are trying to find out the identity of the gobs that were riding on a broom. Broom riding is evidence of witchcraft and so those practicing it must be witches, or at least be on familiar terms with them. Thus the sense of urgency regarding the interrogation of these two citizens. The relationship between witches and goblins will be further explored in future postings and pages...stay tuned!
I have to admit, I look at these goblins I've created and realize that they don't look like what the stereotypical Brian Froud-ish-designed goblin is commonly perceived as looking like, if you get my meaning. I mean, goblins are typically shown as less colorful and are usually hornless.
Speaking of Dr. Suess, the hat in panel 4 probably looks familiar. There is probably not another cartoon character's hat that could be so immediately familiar than that of the Cat in the Hat. Maybe Dick Tracy's yellow fedora, or Charlie Brown's baseball cap?