Marvel films are at their best when the heroes and heroines of the storyline go toe to toe with a big bad. This fact was never more evident than in Avengers: Infinity War and Avengers: Endgame when the team found themselves battling the big bad himself—none other than Thanos.
Rumors seem to indicate that the next big bad to stir up trouble in the MCU may very well be Galactus. If fans recall, the last time we saw him was in the second entry into the Fantastic Four franchise, Fantastic Four: Rise of the Silver Surfer.
Comic book fans may know that Galactus is a humanoid that was the last survivor of the end of his own homeworld, that then evolved into a being that had to consume planets to survive and exist. One of his heralds was The Silver Surfer, whose task was to seek out and lead Galactus to any energy-rich worlds that he found.

Image: Screen Rant
In the Fantastic Four film version, Galactus we represented by a massive cloud. As fate would have it, the original form of Galactus and that of the Celestials in Eternals bore a striking resemblance. This factor provides an excellent means of introducing Galactus into the current MCU.
In a recent interview, Ryan and Kaz Firpo, both screenwriters, seemed pretty enthusiastic when asked about the possibility of Galactus making his debut in Phase 4: “Galactus is an amazing, amazing character, and villain. We are, you know, obviously setting the stage for intergalactic, cosmic, megalith confrontations, especially when you kill a space god—and then the space god comes and kidnaps you and plans to judge Earth, I think the door is very much open for the world-eating villains.”
The pair went on to say that Galactus is one of the most iconic characters in the MCU, and they, and the fans, were excited to see him make his appearance.