Futurama - Season 4 -

While it is the fourth production season, Fox broadcast these episodes across its fourth and fifth seasons.

The episode "The Why of Fry" explains that Fry’s cryonic freezing was not an accident but a plan orchestrated by the Nibblonians to ensure he would be in the future to save the universe. Futurama - Season 4

In "Leela's Homeworld," it is revealed that Leela is not an alien but a mutant whose parents gave her up to the Surface World orphanage to provide her with a better life. While it is the fourth production season, Fox