The Ion Cannon is a special weapon of the game Star Trek: Armada. It inflicts a lot of damage when impacting an opposing ship. It is researched at the Weapons Center. It looks like this:

The Ion Cannon is also used by the campaign ships Martok's Negh'Var and Toral's Negh'Var. When trying to use this special weapon on a ship protected by a Corbomite Reflector, the damage will be reflected back to the casting ship. The Shield Remodulation on the other hand, protects from it, as well as an active Phase Cloak.

The Mother Entity is also equipped with a derivative of the Ion Cannon, named Plasma Ball. The Plasma Ball is not considered to be a special weapon but standard equipment of the Mother Entity. It inflicts the same damage and costs the same amount of special weapon energy but is never used as the Mother Entity has up to 500 energy and one shot of the Plasma Ball requires 600 energy. It is therefore useless to the Mother Entity (definition bug).