In Guardians of the Galaxy, the Collector explains the creation of the Infinity Stones to the film’s heroes. These stones form a major part of the plots in Avengers: Infinity War and Avengers: Endgame.
While the Collector scene plays out, the history of the universe and the stones is depicted in the background. This has led to a whole new fan theory. It speculates that one of the planets in the scene is Taa, home of Galan. He is a humanoid who becomes Galactus, the Devourer of Worlds.
During the sixth incarnation of the Multiverse, Galan became the sole survivor when the universe’s renewal cycle was completed. He then merged with the essence of the Sentience of the Universe and became Galactus.
According to the theory, the Sentience of the Universe is what is seen in the Collector’s lecture about the creation of the stones. Some fans also believe that the design on Galactus’s helmet can be seen on the Celestial’s staff.
If this theory about the origin of Galactus had turned out to be true, then the final Easter egg in the movie was solved—after a fruitless four-year search by hard-core fans.
Alas, director James Gunn shut down the rumors in 2018 by replying to a tweet: “Getting lots of messages about Galactus in the Collector scenes. No, he’s not there in any way.”