Bannermen

The Bannermen are a sapient humanoid species from outside the Milky Way, able to travel through space and apparently time as well.

Biology
Bannermen appear as Human-like humanoids, at least externally. Internally, they have purple blood, and possess super strength. It is possible, but unconfirmed, that Bannermen can live for thousands of years.

History
Having previously rendered their world uninhabitable, they invaded the peaceful world of Chumeria and massacred the native Chimerons, driving them to near extinction.

Even after clearing the planet for themselves, they insisted on tracking the fugitive Chimeron queen to Earth to ensure the species would be completely annihilated. In that they failed, as the group which traveled to Earth in 1959 ended up defeated and arrested, and the queen escaped to another world with her new mate and child.

Appearances

 * Doctor Who, season 24 (Seventh Doctor) - Delta and the Bannermen (1987)