Ironheart gave us the Marvel villain everyone wanted, but his true form is hiding in the finale's best Easter egg

Ironheart finally pulled back the curtain on the man pulling the strings – and supplying the Hood – behind Parker Robbins' daring grab for power in Chicago. But while he wears one face, fans will be pleased to know that his comic-accurate form is hiding in plain sight.

Spoilers for the Ironheart ending follow. You have been warned!

Scroll along to 27:46 in the finale on Disney Plus and you'll see the moment in question. During Mephisto and Riri's interaction post-Hood's defeat, the devilish villain dips his spoon into his cup of coffee. In the reflection, you can see Mephisto's true form: a demonic figure, complete with red skin.

Of course, that more closely resembles his usual comics look, a devilish bearded man that's more Hellboy than Rasputin-style hellraiser.

First appearing in Silver Surfer #3 back in 1968, Mephisto has long been the devil on the shoulder for several Marvel heroes and villains, most notably Spider-Man in the much-maligned story arc One More Day. There, Mephisto saved Aunt May's life in exchange for the end of Peter Parker and Mary Jane's marriage.

Speaking to Slash Film, Ironheart executive producers Zoie Nagelhout and Sev Ohanian revealed that Dormammu, not Mephisto, was originally discussed for Ironheart's Big Bad.

"Initially, there was conversation of following the comics, which involves leading to Dormammu, who is, in publishing, the entity behind Parker's powers," Nagelhout explained. "But as we explored that and as we sort of broke down what that would look like, we realized that there was a better thematic match with Mephisto."

Ironheart is now streaming on Disney Plus. For more, be sure to discover all you need to know about the imminent beginning of Marvel Phase 6. Then dive into how to watch Marvel movies in order, from Iron Man to Ironheart.