Herbicidal Maniac is a minigame in Mario Party 7. Similar to Whack-A-Mole, in this minigame, you and your partner must shoot the Piranha Plants that come out of the grid of Warp Pipes before you before they disappear into the pipe again. For each Piranha Plant you kill your team gets a point and which ever team gets three points first wins. Besides Piranha Plants, bombs will also appear and disappear from the Pipe grid but shooting one of those will result in a Piranha Plant infestation.