On a similar note regarding hidden items in cartoons that your readers may enjoy. I used to love trying to find these when I was younger.

Albert "Al" Hirschfeld was an American caricaturist best known for his black and white portraits of celebrities and Broadway stars.
Hirschfeld is known for hiding his daughter Nina's name in most of the drawings he produced after her birth.
The name would appear in a sleeve, in a hairdo, or somewhere in the background. The number of NINAs concealed is shown by an Arabic numeral to the right of his signature.
Generally, if no number is to be found, either NINA appears once or the drawing was executed before she was born.
Almost all of Hirschfeld's limited edition lithographs have NINAs concealed in them. However, the pursuit is made that much harder because there is no numeral to the right of the signature to guide you.

Most Bizarro cartoons include one or more of these devices hidden somewhere in the cartoon:
• an eyeball (the Eyeball of Observation),
• a piece of pie (the Pie of Opportunity),
• a rabbit (the Bunny of Exuberance),
• an alien in a spaceship (the Flying Saucer of Possibility),
• the abbreviation "K2" (referring to his children Kermit and Krapuzar),
• a crown (the Crown of Power),
• a stick of dynamite (the Dynamite of Unintended Consequences),
• a shoe (the Lost Loafer),
• an arrow (The Arrow of Vulnerability),
• a fish tail (The Fish of Humility)
• an upside down bird (the Inverted Bird)
Piraro has begun indicating how many symbols are hidden in each strip with a number above his signature.