Galactus

Galactus is a cosmic being that consumes the life energy found in planets for sustenance. During the previous multiversal cycle, the Sixth Cosmos, he was a mortal Taa-an named Galan of Taa. As his universe was dying, he was approached by the Sentience of the Sixth Cosmos (the precursor to Eternity), fused with its essence, and passed on to the next cycle, the Seventh Cosmos, where he would emerge as Galactus after an incubation period. He succeeded Omnimax.

Galactus has appointed several Heralds, such as the Silver Surfer, to both scout for suitable worlds that he can devour and signal him to come to them. He empowers them with the Power Cosmic. Despite being the Devourer of Worlds, he holds no malice toward any living thing and simply does what he must do to survive. By his own admission, he is destined to one day give back to the universe infinitely more than he has ever taken from it.