From Halopedia, the Halo wiki
This rank is almost identical to the Spec Op Grunts, the Banished employ Prowling Grunts, this Grunt Squad is lead by a pair of Elites to stealthily scout around or for reconnaissance & kill enemies, they are equipped with active cameo and are faster than standard Grunt Squads. They are employed by Arbiter.
Prowling Grunts are core infantry can perform decent against infantry and aircraft, but terrible with vehicles.
List of appearances