Kerberos is one of four natural satellites of Pluto. It is the moon where the Kerberos Mission crew consisting of Shiro, Samuel Holt, and Matthew Holt, were reported missing five months after leaving Earth and presumed dead due to pilot error. They were, in truth, captured by the Galra Commander some time after landing on Kerberos while collecting ice samples, and taken as prisoners of the Galra Empire. These humans are the first to travel so distantly through Earth's solar system. Shiro is the only known crew member to escape alive a year after his capture, while Matthew Holt was freed by unknown rebels at some point and remains missing. Samuel Holt's status and whereabouts are unknown.
According to Pidge, it takes the futuristic technology of Earth spacecrafts "months" to reach Kerberos. Samuel Holt implies the total intended mission length would be two months when he describes how the crew will be eating freeze-dried peas for that amount of time. The Blue Lion and pursuing Galra warship travel from Earth to Kerberos in a matter of moments. To contrast, New Horizons, launched in 2006, took 9.5 years to reach Pluto.
- Like many planets, Kerberos is named after a mythological figure, in this case the three-headed dog guarding the Underworld in Greek mythology.