Portable holo-pedestal

Portable holo-pedestals are portable, cylindrical holographic projectors and communications devices used by the Covenant. They are frequently placed in Covenant encampments in the field and are used by the Hierarchs to deliver speeches and sermons to motivate the Covenant troops.

Trivia
In both Halo 2 and Halo 3, the player's targeting reticle tracks the hologram (though it doesn't turn red) and a melee treats it as an enemy.

List of appearances

 * Halo 2
 * Halo 3
 * Halo: Reach
 * Halo 2 Anniversary