Dynabombs are an infinite supply of bombs that the player can lay at any time (s)he doesn't have anything else to lay. They explode in a cross shaped pattern, and may have strange results when they kill enemies. (For example, Yam Yams will only give off the center element of their pattern.)

This pickup allows Dynabomb explosions to penetrate brick walls, rather than stopping at the first wall. Picking up 2 of these will only net you extra points.