250mm strike cannons were the back mounted armament for the thor combat walker of the Terran Dominion in the early stages of the Second Great War. The thor could use these four cannons to bombard a target, dealing heavy damage to a target. Raynor's Raiders had the ability to deploy thors with an improved 330mm barrage cannon during the early stages of the Second Great War. In the war's later stages, the weapon was replaced with the Punisher cannon by the Terran Dominion.
The thor attacks an enemy ground unit or structure using the cannons on its back. The target unit is stunned for the duration and takes 500 damage. The thor cannot move or attack when using the ability.