Senior Citizombies are a form of evil undead created by Grandfather, who can zombify people through touch.
|Behind the Scenes|
|Universe||Kids Next Door Universe|
When turned into one, a person becomes extremely old and decrepit to the point of being corpse-like in appearance, with other zombie-like qualities such as yellow pupil-less eyes, the zombified person's physical capabilities are greatly increased though. Like Grandfather himself, senior citizombies can turn other people into their kind just by touching them. Senior citizombies appear to be nearly unkillable, being able to survive the shock of the Moonbase's "fall" without even getting harmed. Victims of zombification do retain elements of their personalities, but lose their free will and become Grandfather's evil slaves regardless of who they are.
The first people turned into senior citizombies were the villains at the convention center, starting with Toiletnator. This already-sizable army then proceeded to invade all the KND treehouses, zombifying everything in their way in the process, until the entire world was under Grandfather's control, eventually even seizing the KND Moonbase. The people of Earth were only returned to their normal selves when Grandfather was defeated and decommissioned by Numbuh 0 and Sector V.
Age-o-tonic Birthday Suits were modified by Numbuh 2 to prevent zombification after the epidemic began, but were only partially complete by the time Numbuh 2 himself was turned into one. When Numbuh 1 put his team into the suits near the end of the film, their bodies are only partially covered and the parts that aren't are still zombified and still evil.
An odd thing to note is that very close friends of Grandfathers relatives, notably Sector V, and Numbuh 362, take some time to be transformed, as rather than an near-instantaneous transformation seen in the villians and normal KND Operatives, they require time to be transformed, Numbuh 2, 4 and 362 all being examples of a resistance to the transformation. Numbuh 2 is shown to be zombified slowly, Numbuh 4 screams for a significantly longer time than normal operatives, and Numbuh 362 required five zombies to hold her down to complete the process.
It is shown that the zombification process is slowed greatly by having the Book of KND, or completely halted if the zombie's hold is broken, as shown with Numbuh 0.