From Halopedia, the Halo wiki
A cargo walker is a powered exoskeleton used by the United Nations Space Command that is utilized to transport cargo. At approximately three meters tall and about two meters wide, the cargo walker moves with legs and pads. This design allows the walker to move smoothly on concrete, but makes movement difficult on muddy or rocky terrain. In July 2553, the 717th Xeno-Materials Exploitation Battalion used several cargo walkers during their operations on Gao.
List of appearances