Asurans

The Asurans, referred to as Replicators by the Tau'ri, were a technological life-form created by the Lanteans to fight the Wraith in the Stargate Universe.

The Asurans, though appearing as humans, were actually constructed of millions of nanites, giving them abilities such as shape-shifting, increased strength in human form, the ability to scatter inside an enemy to attack them (organic assimilation) and self-replication.