Galactus wants Franklin Richards primarily because Franklin possesses immense cosmic powers that could either satiate Galactus's insatiable hunger or be harnessed by Galactus for his own purposes. Franklin is considered a Beyond Omega Level mutant with the power to create universes, dimensions, and manipulate reality, making him extraordinarily powerful. In the 2025 movie "Fantastic Four: First Steps," Galactus demands Franklin in exchange for sparing Earth. This is because Galactus is aware of the cosmic energies within Franklin and likely wants to consume or control these powers—possibly to rid himself of his cosmic hunger or even to make Franklin his next Herald. In the Marvel comics, Franklin is so powerful that he once made Galactus his Herald, showcasing their complex connection. Therefore, Galactus’s interest in Franklin is driven by both the child's extraordinary power and the potential for Galactus to use Franklin's abilities to create new worlds to feed on or to pass on his hunger in a new form.