Here's who that mysterious figure was in the credits scene of "The Fantastic Four: First Steps" and how it sets up Doomsday.

First Steps to bring you an in-depth breakdown of all the Marvel Studios movie's biggest Easter Eggs, comic book references, and cameos. Check it

In their MCU debut, the Fantastic Four become a Fantastic Five with the arrival of Reed and Sue's son, Franklin Richards. Worries that he might not be "normal" are confirmed in Fantastic Four: First Steps when Galactus recognises that the boy can wield an unlimited energy known as the Power Cosmic (presumably because of the "cosmically compromised DNA" shared by both of his parents).

First Steps will feature two credits scenes, and one has major implications on the future of the Marvel Cinematic Universe.

We call him our Godfather. He’s looked after us," the actress said of Downey's role on the set of the next 'Avengers' movie

After a number of false starts, the Fantastic Four have another feature adaptation in the retro-pastiche Fantastic Four: First Steps. This isn’t the first time Mr. Fantastic and co. have appeared onscreen; They were last seen in Josh Trank’s Fantastic 4 (stylized as Fant4stic) and Tim Story’s Fantastic Four films for Fox.