Pop cannon

A pop cannon is an object in Dr. Mario World. Pop cannons have launchers at the top and the bottom, as well as a body marked with arrows pointing up and down. These objects are introduced in version 1.4.0 when World 17 was added, although these objects can be found in earlier worlds in later stage updates.

When a color capsule matches the color of a pop cannon or that it is eliminated, two cannonball will be fired from the launchers at the top and bottom in a straight line, causing viruses or objects in the way to be eliminated. The only object that can block cannonballs are Empty Blocks. In versus mode, the only way for rotating cannons to appear are through assistants, namely Broozer and/or Galoomba, where the former may change two viruses into pop cannons in the beginning while the latter may change two of the viruses generated after clearing all viruses into pop cannons.

In-game description

 * "Match a pop cannon with pieces of the same color to fire cannonballs both up and down."