Koopa Zombie

Koopa Zombies are a type of mutated, Bowser-like creatures which were created when humans came into contact with the garbage of Bowser and the Koopalings. Koopa Zombies show little to no intelligence, though they seem to be driven by the desire to blindly follow Bowser, whose surname, Koopa, they continually chant.

In The Adventures of Super Mario Bros. 3 episode "Recycled Koopa", after being exposed to the dumped garbage of Bowser and the Koopalings, the populace of Brooklyn begin to change into Koopa Zombies, who proceed to aimlessly wander the streets of the polluted city. When Bowser learns about the hidden power of the garbage, he proceeds to attack New York City and order the zombies to hunt down and attack Luigi and Mario wherever they go, using enemies like Bloober Babies, Dry Bones, Bob-ombs, and Firesnakes as backup and ammunition.

After being chased through the city, Mario begins to mutate into a Koopa Zombie himself, and while Koopa starts to load up his Crud Cannon with more of his garbage to mutate the rest of the city's human populace into Koopa Zombies and other animals into his minions (e.g. seagulls into Paragoombas and fish into Spiny Cheep Cheeps), the brothers scurry to build their Trash Smasher, a vehicle powerful enough to recycle all forms of garbage and counteract the effects of the Koopa Zombie magic. Before Koopa can mutate the entire human race in the Real World and just after Mario's mutation is complete, Luigi uses the Trash Smasher to clean the Koopas' garbage and turn the human populace of the city, as well as Mario, to their original, normal forms. Afterwards, the brothers modify the Trash Smasher to make it flight-capable and chase Bowser's Doomship out of the city.