Damage and Knockback
In Bowser jr.'s Down Special, in which Bowser Jr. will open a hatch from his Junior Clown Car, spawning a Mechakoopa. The Mechakoopa travels the entire distance of Final Destination, and will turn around upon coming to the end of the stage. If it does not hit anybody or is not picked up, it will begin to flash red, indicating it is about to explode. The explosion causes about 5-6% damage with low knockback. If it hits an enemy, it will do a short hop, bringing the character with it and causing 3-4% damage, and then explode, causing the same amount of damage as above with slightly higher knockback. If picked up and thrown, it will explode on contact with a solid surface, but if it hits an enemy, it will function as if it had walked into an enemy. Bowser Jr. cannot spawn two Mechakoopas.
Customization
Bowser Jr. can switch this move with two specials: Mechakoopa: Default special. Impatient Mechakoopa: The Mechakoopa explodes on contact with the floor, yet travels a fair distance. Big Mechakoopa: Spawns a bigger Mechakoopa with can only explode when thrown. Walks slowly. Has a short fuse and bigger explosion radius.