Magic Weapons. The animated cannon's weapon attacks are magical.

Stable. Whenever an effect knocks the animated cannon prone, it can make a DC 10 Constitution saving throw to avoid being knocked prone.

Tip Over.  The animated cannon tips over onto its side if it is knocked prone.  A prone animated cannon can't right itself, can't move, and automatically fails Strength and Dexterity saving throws.

Wheeled Carriage.  The animated cannon can't move up or down stairs, automatically fails any checks made to climb, and it moves at a third its speed instead of half speed in difficult terrain—moving 1 foot in difficult terrain costs it 3 feet of speed.

Cannon Ball. Ranged Weapon Attack: +6 to hit, range 600/2,400 ft. Hit:  44 (8d10) bludgeoning damage.