From Halopedia, the Halo wiki
Manufactured by AMG Transport Dynamics, Civets were the second most common military ATV in CMA service by 2329, being only superseded by the M12 Warthog. On March 18, 2526, a convoy of Civets was employed by the Biko Independence Army and other insurrectionists on Seoba, Biko's third moon during an attack by the United Nations Space Command.
Civets are hulking, tracked all-terrain vehicles that can be fitted with cargo boxes or cargo beds. As such, they are capable of ferrying troops and supplies across terrain that might not be traversable by other transports. A Civet may also have a multiple rocket launcher on it. The ATVs are powered by combustible fuel.
List of appearances