Marvel's Eternals film promises to bring us to the "beginning" of the MCU, and we've been getting some concept art of the massive (and ancient) Celestials. We don't really know how they play into the story, but we got some new concept art for one of the creatures.
Check it out:
What's interesting is it looks like the Celestial is being placed adjacent to a planet. Of course, it could just be a small moon, but a lot of people are positive that this will be kind of a teaser to Marvel's most famous Celestial—the Devourer of Worlds a.k.a. Galactus.
Galactus is usually referred to as one of the most infamous villains in the MCU, and it's likely we would see him clash with the Fantastic Four. With the Rise of Silver Surfer film, we got Galactus in the form of a giant cloud, but with the MCU introducing Celestials, we could have him in full giant form, ready to devour a planet.
This is also just a side bit, but it's said that the Celestials were the ones who created the Eternals. If we get a look into that process, maybe it can also be a teaser of how Galactus creates the Silver Surfer. This is just my guess, but it's likely Marvel could be planting seeds as early as now.
We don't know when we'll get the first preview for Eternals, but with the movie set to come out next year, we could get something attached to the release of Black Widow in May.
Eternals comes out Nov. 6, 2020.
See Also: Eternals' Gay Character Will Be Married And Have A Family