Exploder

An exploder is a stage feature in the shape of a bomb from Dr. Mario World. When a color capsule matches the color of the exploder, the exploder eliminates objects, such as viruses, in its adjacent tiles. They mostly appear in Stage Mode, but in Versus Mode, they can appear based on an assistant, or they can also appear with Dr. Baby Mario's skill.

In-game description

 * "Match an exploder with pieces of the same color and it'll...explode!"