WARNING: The following article contains spoilers for Warner Bros.' Shazam!, in theaters now.

If you're walking out of the theater after seeing Shazam!, and frantically Googling what the hell that was in the film's mid-credits scene, then search no more.

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You cheered when the Shazam Family united on the big screen, and you were surprised when Superman showed up at the end of the film. However, the mid-credits stinger also introduced a new villain in the form of a talking, hyper-intelligent and surprisingly treacherous worm. Yes, your eyes did not deceive you: Mark Strong's imprisoned Thaddeus Sivana really did talk to worm outfitted with a speaking box.

You can call him Mister Mind.

Mister Mind

Although he may not look like it, Mister Mind is one of the biggest foe's in Shazam's comic book mythology. Created by Otto Binder and C.C. Beck, the villain debuted in 1943 in Captain Marvel Adventures #26 (when the superhero was still known as Captain Marvel). Just like in the film, Mister Mind is a worm whose voice can be heard through a talking box. He's actually a highly intelligent alien, and he has been a thorn in Shazam's side throughout the decades. His powers include telepathy and mind control and super-silk (seriously). And, while he may not be immortal, he is very, very old.

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What's more, the character is most famous for founding the Monster Society of Evil, a monstrous squad considered the first supervillain team in comic book history. Over the Monster Society has been comprised of such obscure characters as Oom, Mister Who, Goat-Man and Mister Banjo (no, we're not making up those names). Because Mister Mind doesn't pose a physical threat to Shazam, he uses others to do his bidding, like the Monster Society of Evil and, later, Doctor Sivana.

Sure, the character may have began as a goofy addition to Shazam's rogues gallery. However, Mister Mind has become a terrifying threat that can't be taken lightly. In DC's recent New 52 comic series Shazam!, by Geoff Johns and Gary Frank, a main source of inspiration for the film, Mister Mind formed a union with Sivana in a scene similar to the mid-credits scene.

Mister Mind, on the cover of DC's Shazam! #3 (2019), by Dale Eaglesham and Alex Sinclair

The stinger may not come as much of a surprise if you were paying attention in the film. Right at the beginning of Shazam!, when a young Doctor Sivana is taken to the Rock of Eternity, you can see Mister Mind held inside a bowl. Later, when Billy Batson travels to the Rock, the bowl is shattered and empty, suggesting Mister Mind was freed when the Seven Deadly Sins of Man were awakened by Sivana.

Therefore, Shazam! slowly built to the introduction of one of the character's biggest comic book villains. Now, Mister Mind is ready for the sequel, and he will most certainly not come alone.

Directed by David F. Sandberg, Shazam! stars Asher Angel as Billy Batson, Zachary Levi as Shazam, Mark Strong as Dr. Thaddeus Sivana, Djimon Hounsou as the ancient wizard Shazam, Grace Fulton as Mary Bromfield, Jack Dylan Grazer as Frederick “Freddy” Freeman, Ian Chen as Eugene Choi, Jovan Armand as Pedro Peña, Faithe Herman as Darla Dudley, Cooper Andrews as Victor Vásquez and Marta Milans as Rosa Vásquez. The film opens Friday nationwide.