Skar'wa-pattern Mantis
From Halopedia, the Halo wiki
The Anti-Aircraft Battery[1] is a Covenant ground-based stationary anti-aircraft emplacement. It fires bolts of plasma that are extremely damaging. A single round can severly damage a C709 Longsword-class Interceptor.
Background
The bolts that it fires are in a teardrop shape similar to shade and plasma rounds and in an almost straight trajectory. The plasma bolts are extremely powerful, since even their wake is able to take down a Longsword. However, the battery must cool off and release its excess plasma after every shot. This makes the AA battery vulnerable to infantry and ground vehicle attacks. It is unclear about how powerful these weapons are. During the Battle of Installation 00, an it was reported that one AA gun could "tear the Dawn apart", implying that an AA battery could destroy a UNSC Frigate. Troops are often stationed on and around AA guns to safeguard them from ground forces.
Appearances
In Halo 3, the AA Battery can be seen in the level The Storm and is the main objective of the level, which is to destroy it so that Lord Hood can start attacking the Prophet of Truth's Dreadnought in order to stop him from activating the Portal. An AA Battery under construction can be seen in the level The Ark.
Gallery
The Covenant often make use of Phantoms to construct their AA in good time, as seen in Halo 3.