Cannonlance

Weapon (lance), rare

This lance looks like a modified cannon with a wooden vamplate. A chain dangles from the pointed front of the lance to the cannonlike base. This weapon has the heavy property.

Once on each of your turns, you can replace one of your attacks with the lance to make a special ranged attack with it. When you do, you fire the front of the lance at a target that you can see within 20 feet of you. The blast emits a thunderous explosion audible out to a range of 300 feet. On a hit, the target takes 3d6 piercing damage (without adding your Strength modifier), or 6d6 piercing damage if the target is an object or structure. If you hit a creature and roll a 6 on any of the d6s, the target is also pushed up to 10 feet away from you. The chain then automatically pulls the point back to its base, where it magically reattaches. You can use a bonus action when this happens to pull yourself up to 20 feet to an unoccupied space directly between you and the target.

They knew the knight was coming well before he rode into town.