A rotating cannon is an object in Dr. Mario World. As its name implies, rotating cannons are shaped like turrets and can rotate so that the muzzle will be facing a different direction. Although the first world in stage mode to introduce it is in World 25, these objects are added since version 2.2.0, in which certain assistants and the handy box can generate them, and a few summits in Skill Summit has these objects.
Every rotating cannon will rotate 90 degrees clockwise when a capsule lands without eliminating something or making a match, unless the rotating cannon(s) are contained inside another object besides clouds. When a color capsule matches the color of a rotating cannon or that it is eliminated, a cannonball will be fired from the muzzle 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 Bone Goomba and/or Conkdor, where the former may change two viruses into rotating cannons in the beginning while the latter may change two of the viruses generated after clearing all viruses into rotating cannons.