- "Overconfidence in our technologies has been our undoing. The entities learned from the very means that were employed to stop them. They have become a plague on our galaxy that is annihilating everything in its path."
- — Thor
The Replicators are a highly-advanced machine race from P3S-517 in the Milky Way galaxy and are capable of reproducing themselves indefinitely, consuming all available resources in an area to create more of themselves whose only objective was to, as the name implies, replicate themselves endlessly. They would consume all available resources in the process, stripping entire worlds bare and exterminating any and all life that stood in their way. Because they had only one directive, communication or diplomacy with the Replicators was impossible until they evolved to the point where they could create human-form Replicators which possessed an ability to think beyond the original command to self-replicate. Thanks in large part to the four-thousand year war against the Asgard, the Replicators as Earth knew them gained an extreme resistance to energy weapons, but were cursed with an incredible weakness to phaser weaponry as a result. Despite their vulnerability to human technology, however, they remained fully capable of invading the Milky Way Galaxy and very nearly destroying everything existing there.
It is believed that all Replicators in the universe were destroyed when Replicator Carter led the entirety of the machine horde within range of the Dakara superweapon, which had the ability to break them apart at the subatomic level.