Gatherers are Forerunner machines whose primary function is to gather specimens of different species and to transport them for study and cataloging. So far, these machines have only been observed operating from Line Installation 1-4 on an Unidentified moon.
Gatherers consist of a fairly large main body with three red eyes and a holding tank for captured specimens on their backs, filled with a purple liquid. They have eight tentacle-like clawed arms, two much smaller arms, and four legs, although they are usually seen floating through the air. Gatherers are armed with an energy weapon similar to but more powerful than the Sentinel Beam, and is located below the tentacles. Much like the Sentinel Beam, the weapon can be detached and used as a hand-held weapon.