ADVENT Turret (XCOM2)
ADVENT turrets are fully automated, stationary guns. They have high armor, but low health, such that it may not be worth shredding their armor since they usually go down in two hits anyway. Turrets can fire twice per turn. Turrets are vulnerable to the Specialist's Haywire Protocol. As the story progresses, they do acquire more yellow armor pips.
On occasion, you will find turrets located on top of ADVENT facilities: for an easy kill, smack 'em with a grenade and they'll smash through the floor for an instant kill (also completing a Achievement).