While Reed Richards/Mr. Fantastic and Sue Storm/Invisible Woman's (Pedro Pascal, Vanessa Kirby) son Franklin Richards was at the centre of The Fantastic Four: First Steps' plot, Doctor Doom's appearance has left fans intrigued about the MCU character.

Doomsday theory explores how the Fantastic Four might travel to Earth-616. It suggests Reed Richards uses Galactus’ ancient ship tech, combined with his own inventions, to build multiversal transport and rescue Franklin Richards from Doctor Doom’s grasp.

Franklin Richards, the superpowered baby of Mister Fantastic and Invisible Woman, is played by a group of real-world babies in Fantastic Four: First Steps. However, in several scenes, the little guy is depicted through CGI.

How Franklin Richards, the power cosmic and Doctor Doom's appearance in "The Fantastic Four: First Steps" credit scene affects "Avengers: Doomsday."

In a 1982 arc by John Byrne, Franklin gets frustrated trying to solve a Rubik’s Cube and uses his powers to age himself into an adult body, though he couldn’t actually gain more emotional maturity. He winds up going back to being a kid, placing restrictions on his own abilities to allow him to have something of a normal childhood.

First Steps reveals Galactus' intention to make Franklin Richards his heir, while hinting at Doctor Doom's potential plan to save the Multiverse.

As the rest of the Fantastic Four mourn her, Reed puts their son on her chest to say goodbye, and then he miraculously resuscitates her. The parents spend most of the movie worried that Franklin might be some kind of monster like Galactus,

The Fantastic Four: First Steps is off to a strong start at the box office, with a global tally of $218 million for its opening weekend. In the US, Marvel's first family enjoyed the fourth biggest domestic opening of 2025, behind A Minecraft Movie ($162 million), Lilo & Stitch ($146 million), and Superman ($125 million).