(If the name refers to an individual of the species whihc was captured on Earth or if it refers to the species itself remains unknown. We will treat it as such here)
Io are 3 meters tall crustacean humanoids who developed a space faring civilisation. Io are covered in thick carapace. They possess 2 digits on their feet and hands. Females are red but it remains unknown if males are of the same color.
An individual from this species was kept prisoner on Earth by the US Army during the later part of the twentiest century.
Source: Escape from Planet Earth.