Like all modern superhero movies, getting the full effect of Warner Bros.’ Shazam requires that you sit through a few minutes of credits in order to see a scene featuring hints about things that might come to pass in future sequels or other films set in the shared universe.
Interestingly, both of the Shazam scenes that play after the proper film is done focus on things you actually see for the first time over the course of Billy Batson becoming a superhero, and the more cryptic of the two stingers establishes an important part of Shazam’s mythos from DC Comics suggesting that when next we see him, it’s not just Black Adam that he’s going to have to worry about.
Early on into Shazam there’s a scene in which a young Thaddeus Sivana meets the ancient wizard Shazam who’s summoned him to the Rock of Eternity believing that the young boy might make a suitable new champion worthy of wielding his vast magical power. As Sivana makes his way into Shazam’s layer, there’s a brief shot showing off some of the many artifacts the wizard’s collected over the years like a perpetually-burning string instrument, the demon-harnessing orb that eventually grants Sivana his Shazam-like powers, and a tank containing a large caterpillar.
When Billy Batson eventually makes his way to the Rock to become Shazam, the burning instrument is still there, Savanna’s long since stolen the orb, and the caterpillar’s seemingly escaped from its now-broken enclosure.
The vibrant lepidopter doesn’t make another appearance for the rest of the film itself, but half-way through the credits, we’re brought to a scene where an incarcerated Sivana is spending his time drawing magical runes all across the walls of his cell in an attempt to escape. As Sivana’s only piece of chalk breaks, the scientist collapses in a fit of frustration, but his moment of anger is suddenly interrupted by laughter from someone in the room that he can’t initially see. It’s the caterpillar, who is sentient, and he’s got some thoughts about both Sivana’s predicament and humanity as a whole:
Primitive. Simple. You walking, talking monkeys with your cave drawings. You assume there’s only one way to gain magic. No, no, no. There are more ways than a mind can imagine. I name the gods, doctor. Not the other way around. Oh what fun we’re going to have together. The seven realms are about to be ours.
While the caterpillar never says his name, director David F. Sandberg (who also voiced the character) has explained that he is, in fact, Mister Mind.
DC’s Mister Mind is indeed an insect-like creature and one of Shazam’s odder villains from his Golden Age days as Captain Marvel in Fawcett Comics’ books. He was first introduced in Adventures of Captain Marvel #22 as the mastermind behind a coordinated attack on Shazam’s life that he directs over the radio. Though the villain initially lives in a dreadful castle on the surface of Venus, he develops a hatred for Shazam (and by extension Billy Batson) after he inadvertently intercepts Billy’s news broadcasts from Earth where he works as a radio reporter.
At first, Mister Mind calls upon Captain Nazi and orders him to try and beat Shazam on his own, but when that initial plan fails, the insectoid reveals that his actual scheme to defeat the hero involves bringing together the whole of his rogues gallery to form the Monster Society of Evil.
In his original incarnation, Mister Mind isn’t exactly as interested in Nazism as much as he was just very into the concept of evil itself. Allying with the Axis, he explains, was merely a means to an end in his ultimate pursuit of wreaking havoc upon the world and making Shazam his specific target.
After making his debut and subsequently dying during that first “Monster Society” arc, Mister Mind would disappear from the comics world for decades following Fawcett Comics’ shuttering and the Captain Marvel comics rights moving over to DC Comics. In the early ‘70s, Mister Mind remerged and became one of Shazam’s most regular foes, and as time has gone on, the specific nature of the villain’s powers and his reasons for being evil have shifted as different writers have incorporated them into their stories.
For the most part, Mister Mind’s comics power set has been centered around abilities like telepathy and mind control. But in Geoff Johns, Grant Morrison, Greg Rucka, Mark Waid, Joe Bennett, Jack Jadson, Belardino Brabo, and Keith Giffen’s 52 series, Mister Mind goes through a drastic metamorphosis that transforms him into a hyperfly capable of devouring the very fabric of the universe itself. Mister Mind doesn’t allude to having any of those abilities in Shazam, but his comments about the seven realms and the nature of the DCEU’s magic are worth taking to heart.
In Johns’ ongoing Shazam comic, the curious creature hatches a plan to destroy the entire Shazam family by forcing them to split up and leave the Rock of Eternity for one of seven magical, kid-themed lands—the “Funlands, Gamelands, Darklands, Monsterlands, Wildlands, Wozenderlands, and Earthlands.” While each of the lands might seem as if it’s merely a fantastical dimension meant to reflect the imaginations of children, the mystical power flowing through them all has the potential to be harnessed for incredible feats of creation or destruction, making them places the Shazam family needs to protect for the greater good.
Mister Mind doesn’t mention any of the Magiclands in Shazam, but his mentioning other means of tapping into magic and the fact that he was, at one point, trapped on the Rock of Eternity suggests that that aspect of the character’s lore might be incorporated into Shazam 2. It would also make sense considering that Black Adam’s been a member of the Monster Society.
There’s no reason to assume it’s the case, but Shazam’s post-credits scene—a joke about Shazam not having Aquaman’s powers to control sea life—might also be a nod to Zack Snyder’s cryptic “unite the seven” Aquaman tease, suggesting that if and when Mister Mind makes his next appearance, it’s going to take an entire league of heroes to stop whatever it is that he’s planning.