When Entertainment Weekly asked Fantastic Four: First Steps director Matt Shakman if Downey Jr. filmed that post-credits scene, the filmmaker pleaded the fifth. "For others to talk about," he teased. However, Shakman did reveal that it was the Russo brothers who helmed the post-credits scene since it was shot for Avengers: Doomsday.

As the credits finish rolling on The Fantastic Four: First Steps, a quote from Fantastic Four co-creator Jack Kirby appears on screen, saying, "If you look at my characters, you will find me. No matter what kind of character you create or assume, a little of yourself must remain there."

First Steps is the first movie to truly capture the team, being more science-fiction epic than a traditional superhero movie.