Needler Sentinel
From Halopedia, the Halo wiki
The Needler Sentinel can only be found in the level, Quarantine Zone, playing on any difficulty. There is a Sentinel which shoots Needler rounds on the level and, when destroyed, it drops a Needler gun. It can be found on the leftmost side of one of the glowing orange indoor areas. Note that this gun is perfectly ordinary, unlike the Scarab Gun.[1] This Sentinel is an oversight from Bungie's tests with Sentinels using different weapons, and was meant to be deleted.[2]
It is equipped with energy shields, and has the same boosting ability and flight capabilities that a normal Sentinel Major has. The only difference was the Needler rounds.
