Navigator (species)

The Navigators were a highly-evolved phylogenetic life form.

History
One of the planets they originated from was Yisotaga.

Jack Harkness faced them during one of his first missions as a Time Agent.

In 2017, the Navigators allied themselves with the Committee, (COMIC: Station Zero) and began to absorb energy from Earth's heliosphere. Jack explained to Gwen that the reason they did this was so they could "seed" life on other planets.

According to Jack, the Navigators only seeded a new galaxy when they believed the current form of life was reaching its end. (COMIC: World Without End)