Kermit and Miss Piggy watch a Punch and Judy show. Miss Piggy thinks it's too violent, but Kermit defends violence in artistic expression. This exchange immediately followed by two incredibly violent scenes.
Also a bit of a Celebrity Paradox, in a way, as Kermit is defending the artistic merits of puppetry in the face of Ms. Piggy's criticism. As in, puppets arguing about puppetry.
In a movie that features incredibly well-done practical effects and, indeed, some puppetry, plus has a cameo by Frank Oz itself. This one is a whole fridge brilliance bomb.
David's restlessness during the "Bad Moon Rising" sequence isn't just hinting that the werewolf in him is growing eager to hunt; it's also an excuse for him to leave the front door of the flat open, so his quadrupedal were-form won't have to bust its way out. If it had, Alex would have been a lot more alarmed when she got home and found her door or window torn apart, rather than just David missing.
In the finale, were-David bites the head clean off a London policeman as part of the Piccadilly "disturbance". Had David not been killed just minutes later, would there have been a decapitated corpse and its talking head among the victims next time David encountered Jack?