Enforcer Sentinel
From Halopedia, the Halo wiki
Summary
Enforcers are massive robotic automatons that serve to contain major Flood outbreaks. They are protected by an energy shield, but it only seems to protect the "front" on the machine. It is armed with rapid firing pulse beams similar to Needler fire, and mortar-like projectiles. It's mechanical grabbing arms can pick up and crush even heavy vehicles if the driver is careless.
Although it is capable of dropping small bombs and firing red plasma, neither of these are particularly damaging unless you decide to do everything on the spot. Don't let the appearance of the enforcer fool you, it's bark is much worse than it's bite, all the same, it is best to destroy them if needed.
