Outlander

The Outlanders are a race of humanoids from a planet far from Earth.

Biology
Outlanders are externally indiscernible from Humans. Internally, they possess red blood.

Culture and society
The Outlanders have a tremendous thirst for lands, so they have invaded and conquered many worlds, including the Moorwen's homeworld, they use powerful weapons and armors fabricated with a metal capable of harming Moorwens.

It would appear that they seeded Earth in some fashion, either colonizing it or initially seeding it with life, thus quite possibly explaining the unusual similarity between Humans and Outlanders.

It is also interesting to note that the Outlanders had considerable information concerning the Earth and its inhabitants.