Outriders

The Outriders is a race of genetically engineered humanoid creatures with the purpose of serving their maker until they die.

Thanos used Outriders to find new planets inhabited by weak species he would raze. Upon finding a new world, an Outrider would report to Corvus Glaive, who would arrive to that planet along Thanos' Black Order and demand a tribute for Thanos, if the inhabitants refused, that world would be annihilated.