The Mapmakers were once a small group of extremely advanced Adaptoids built on Earth-616 by A.I.M. who set out into the Multiverse via a device called The Augur like the human explorers of old and ended up encountering their future selves who evolved them into a race of godlike A.I.'s that traverse the "Blue" Universal Incursions in an effort to collect the natural resources from each Earth they arrive on.
During an Incursion event, the Mapmakers will finish devouring remains of the Dead Earth they have harvested in a previous Incursion and send a piece of it to the Living Earth, which in turn stops the incursion. However, the piece of the Dead Earth serves as a marker for the Mapmakers to track, and they eventually follow it and the cycle starts again.
The Mapmakers first appeared in the story "Blue Hell" in New Avengers #6, written by Jonathan Hickman and illustrated by Steve Epting.