Midworld is a fictional planet created by Alan Dean Foster for his Humanx Commonwealth universe. Its distinguishing feature is the thousand meter high rainforest that covers nearly all of the planet, making it the most biologically diverse planet in the universe. It is home to a human offshoot known as Midworlders who are slightly smaller than human standard with adaptations that include light green skin and long toes. The novel Midworld (1975) introduced the planet and it is also the setting for the novel Mid-Flinx (1995).