The Mecha Piranha Plant is a non-sentient Piranha Plant robots found exclusively in Waluigi Stadium, a course introduced in Mario Kart: Double Dash!! and returning in Mario Kart Wii and the Booster Course Pass of Mario Kart 8 Deluxe. There are a total of three Mecha Piranha Plants, and all of them are found in a straightforward stretch of the course, one after the other.
Mecha Piranha Plants are larger than the drivers. They move in and out of their pipe like an ordinary Piranha Plant, although at a much slower pace. Mecha Piranha Plants serve only as a wall, and do not spin out a racers if they crash into them.
In Mario Kart 8 Deluxe - Booster Course Pass, the Mecha Piranha Plants were redesigned to appear more metallic, and there is visible mud and rust on them. They no longer move their mouths, possibly to make them appear less sentient.
