Essentially a lightweight combine harvester on a tracked chassis, it is designed for collecting veins from veinholes and delivering them to the Tiberium Waste Facility for processing into chemical missile payloads.
These units were possibly decommissioned following the Firestorm Crisis.
The weed eater is basically a overhauled harvester, meant to collect the vein appendages of a veinhole, and is the only unit in the game that can do this. Weed Eaters have similar armour, health, and speed as a regular harvester and are required to fuel the Nod chemical missile.
In the Official Guide Book released in mainland China, the weed eater is translated as "除草机 (weeding machine)", given the fact Tiberium veins spread fast and invasive as weeds.