Thank you, son! Thank you for reawakening the pure evil that lay dormant within me for these many years... And now, GET OUT OF MY SIGHT!
~ Grandfather upon being brought back.
Monty, Monty, Monty. Did you honestly believe that thirty-nine-gazillion tons of red-hot metal and duct tape would crush me?...You’re out of my will, you brat!
~ Grandfather's last words before he and Monty get decommissioned by Numbuh One.

Grandfather is the main antagonist of Operation: Z.E.R.O. and is by far the most powerful and evil villain and is also the overarching antagonist of the Codename: Kids Next Door series.

He is an extremely powerful and ancient demonic being who once ruled the world before he was overthrown by his elder son, Monty Uno. Many years later, he was revived by his younger son and successor, Father, and began transforming the people of the world into Senior Citi-zombies. Grandfather is very tall and lanky, and significantly taller than a normal person. He had a bald head and a large beard with long, scraggly strands of hair. He is also the grandfather of Nigel Uno (Numbuh 1).

He was voiced by Neil Ross, who also voiced Norman Osborn/Green Goblin in Spider-Man: The Animated Series, the Cyclops The SpongeBob SquarePants Movie as well as Colonel Volgin in Metal Gear Solid 3: Snake Eater.


During the Victorian Era, Grandfather (back then known as Pappy) ruled the world with an iron fist and forced all children to work in his tapioca factories. One day, his son, Monty Uno, discovered the Book of KND, led an uprising of children and defeated his evil father by erasing memories and powers.

During the dawn of the 21st century, Grandfather's other son, Benedict Uno, used the Recommissioning Module on Grandfather, then a decrepit old man, to restore his former self, and expected to work together with him to destroy the Kids Next Door and rule the world alongside him. However, Grandfather shunned his son and ordered him to leave, calling him a failure and claiming that he liked his other son more.

He then revealed his plan: To turn all the kids in the world into Senior Citi-Zombies, as well as everyone who was ever a kid. The villains cheered, until they realized that they all used to be children and that this amounted to every person in the world. They tried to flee, but in vain. Once Grandfather turned all of them into his zombie minions, he ordered them to invade the Kids Next Door's treehouses throughout the world, turn them into zombies as well, and turn their treehouses into tapioca factories. Soon, every nearly KND operative (and presumably every person) on the planet was transformed, save for Numbuh 1, who would re-commission his father, Numbuh 0.

After establishing his rule over the world, Grandfather turned his efforts to finding and destroying the Book of KND, as it could provide children with hope; the only thing that could defeat him. Grandfather arrived near its location just in time to be confronted by his son Monty, who was carrying the book in his back pocket. Monty wrestled with Grandfather until he found the Book of KND. Monty was able to resist Grandfather's power, but soon began to succumb to it.

Monty was able to fight off Grandfather long enough for Sector V to launch the KND Moonbase at him, and seemingly destroyed him. However, Grandfather survived relatively unscathed and emerged from the wreckage, only to find out that he was standing in a Decommissioning Chamber from the Moonbase. Grandfather and Numbuh 0 were both decommissioned once again, and turned back into their harmless, and clueless adult selves.


Grandfather is an uncaring, traitorous, and rebarbative parent who betrays all of the other villains, who were willing to help him, without a second thought and turned them into Senior Citizombies along with the KND. He is also shown to be extremely selfish, deceitful, and manipulative, wanting the entire world for himself simply, so that he can have solitude and tapioca pudding, and making the citizombies loyal only to him.

However, despite his evil intentions, he is shown to be fond of his elder son, Monty (when he is not directly opposing him). Grandfather shows sad disappointment towards the virtuous life that his son chose to have. Before Grandfather's decommissioning at the end of Operation Z.E.R.O., it was revealed that despite Monty's rebellion years ago, he was still in Grandfather's will.

However, compared to his younger son, Grandfather is extremely disappointed and crestfallen with Ben, and views him as disgraceful and cowardly, despite Ben following in his footsteps. He is also displeased and unenthusiastic to see him again after his recommissioning, as Ben hasn't recommissioned him out of love for his father but only so that he could finally defeat the KND.

On top of this, he was unimpressed, and he grows extremely annoyed and obstreperous when Ben points out that unlike Monty, he grows up to be pretty cruel, evil, ruthless, and diabolical, so he blasts him in order to make him shut up. He did, however, showed fear when Ben became Father again while being enraged before he quit working with his brother.

Powers and Abilities

In addition to his demonic heritage, Grandfather possessed several other superpowers similar to his son, Father, but are much more advanced and even a few that his son does not have.

  • Reality Manipulation: Grandfather could warp reality to an extent. He turned people into Senior Citi-zombies; monstrous, geriatric undead who could turn others into zombies as well, through their touch. Although people turned into Senior Citizombies did retain a semblance of their personality, they invariably became the obedient minions of Grandfather and attempted to transform anyone they came into contact with. He was even able to affected inanimate objects, and made them Victorian Era in appearance.
  • Fire Manipulation: He has the power to manipulate fire. His powers over fire are much more advanced than his son.
  • Energy Projection: He showed the power to project heated energized blast form his eyes.
  • Telekinesis: He has telekinetic abilities similar to father himself.
  • Electrokinesis: There would be electrical surges when he was angered
  • Shape-Shifting: Like father, he too can shape-shift.
  • Levitation: Like father, he too can levitate as seen when he was leading his Senior Citi-zombies.
  • Supernatural Strength: He has a degree of superhuman strength, being able to break through tons of metal which he was buried beneath.
  • Invulnerability: Not even 39 gazillion tons of red hot metal 1and duct tape was able to crush him or even hurt him at all.
  • Immortality: This anti-aging is also proven by the fact that he has been alive before the Victorian Era and has lived to the dawning years of the 21st century.


  • Decommissioning: However, his mind is his weakness, as erasing his memories makes him forget the fact that he even has great demonic powers. This makes him a clueless & completely harmless old man.



  • Grandfather was reawakened by using the Recommissioning Module, despite not being a member of the Kids Next Door. This also implied that he was defeated in the past by a Decommissioning Device, despite the KND (7th Age/Futuristic that is) not even existing prior to his defeat. However, it's possible that the Recommissioning Module is able to restore anyone's lost memories, not just people who've been put through Decommissioning.
  • Operation: C.A.K.E.D.F.I.V.E. involved the Annoyingly Cute Triplets Who Lived Upon the Hill, who were enemies of the KND during the nineteenth century. Father referred to the mother of the ACTWLUH as his great grandmother, which would make her Grandfather's Grandmother and one of the triplets his mother. It was shown in Operation: Z.E.R.O., that Numbuh 0 was the founder of the 7th age of the KND and that the 19th century was a totally different age.
  • Grandfather's overall design resembled Aku from Samurai Jack.
  • Grandfather's sons and grandson were among the only characters to never be turned into Senior Citi-zombies.
  • Numbuh 1 Father the Delightful Children from Down the Lane and Sector Z were the only people seen to be totally immune to Senior Citi-Zombification, because they were seen touching the zombies and remained normal. That implied that they would be the future heirs to Grandfather's powers, though it was also possible that they needed to be touched by Grandfather himself to undergo the process.
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