Galactus is a powerful cosmic entity in Marvel Comics, often referred to as the "Devourer of Worlds." He is an ancient being who consumes entire planets to sustain his existence. Originally a mortal named Galan, he survived the destruction of his universe and was reborn in the current Marvel Universe as a god-like force of nature. Galactus possesses immense cosmic power, making him one of the most formidable beings in the Marvel Universe. He is often accompanied by his heralds, such as the Silver Surfer, who seek out worlds for him to consume. Despite his destructive nature, Galactus is not purely evil; he is a necessary cosmic force maintaining balance in the universe.