Cosmic Hunger: Galactus requires unknown energies obtainable only from a certain type of planets in order to sustain his life. The suitable type of planet need not to be one where life is present, but it must have the potential to support life. When recently sated Galactus is incredibly powerful; however, the longer he goes without feeding the more his strength, power, and cosmic awareness wane. Indeed, over one month after consuming a suitable planet his power will have already been reduced exponentially, although in such a hungered state his powers are still far beyond mortal comprehension. In recent times Galactus has been known to go without feeding for numerous months at a time bringing him to the brink of death and reducing his power to such a degree that superhuman teams such as the Avengers, and the Fantastic Four etc. can defeat him. When he first emerged from his cocoon, Galactus could go without feeding for over century before his hunger weakened him to a significant degree. Why the intervals between his feedings has decreased over the millennia is unknown.