| Gender | Male |
| Species | Human |
| Hair color | Soft black |
| Eye color | Black |
| Affiliations | McFist Industries |
| Occupation | Scientist at McFist Industries Student at Mad Scientist University (formerly, graduated) Student at Norrisville High (formerly, graduated) |
| Residence | Norrisville |
| Aliases | Viceroy (by McFist, Randy, Howard and everyone else) Willem (by Ruth and Howard) V Diggity, V-Nasty (by Terry McFist) Science Guy, Guy Who Works for McFist (by Bash) |
| Friends | Hannibal McFist (tenuously, sometimes) The Sorcerer (tenuously) Ruth |
| Enemies | Randy Cunningham as the Norrisville Ninja Jerry Driscoll Stevie Miller |
| Interests | To have his genius be recognized |
| Fears | Stevie Miller |
| Parents | Mother Viceroy (mother) Unnamed Deceased Father |
| Pets | Nicholas Viceroy's other creations Otto Koala Weasel Rabbit |
| First Episode | Last Stall on the Left |
| Voiced by | Kevin Michael Richardson |
| “ | McFist Industries, evil genius Viceroy speaking... | ” |
–Viceroy, "Last Stall on the Left" | ||
Willem Viceroy III is the secondary antagonist in Randy Cunningham: 9th Grade Ninja. He is Hannibal McFist's mad scientist and assistant. He is the evil yet rather refined madman responsible for all of the bizarre robots attacking Randy.
Appearance
Everyday
Viceroy is tall and thin, having dark brown hair with a gray streak, a beard, and black eyes. He wears a lavender lab coat over a purple shirt and lavender ascot, purple pants, glasses with purple rims, and black shoes.
His alternate everyday outfit are a pair of very short royal purple shorts, a black belt with a brass buckle, and white socks with royal purple stripes. He is also revealed to have very hairy legs in this attire.
Summer
He has two sets of summer outfits.
His first set from "Monster Drill" is of a large wide-rimmed red hat, red and white striped sleeveless vest, and red swimming trunks.
His second set from "On the Poolfront" consists of a pink visor, a blue and pink striped sleeveless vest, a magenta waist bag, Prussian blue shorts, and azure blue sandals.
Younger
As a teenager, Viceroy had flatter hair without the current gray streak. He also had yet to grow out a beard. He wore a royal purple varsity pullover with the imprinted letters "MSU" (standing for Mad Scientist University), a light pink undershirt, light dodger blue pants, and purple and white colored sneakers. He retained the same pair of glasses he currently wears.
Halloween
During Halloween in "Let the Wonk One In", he wears a baggy, bandaged outfit hat resembles the Bride of Frankenstein.
Personality
Very dry humored and sarcastic, as well as refined and somewhat effeminate, Viceroy works hard to create deadly robots and monsters to destroy the Ninja. He is McFist's chief mad scientist, but he doesn't care about money or power; he just wants everyone to appreciate his genius. It frustrates him that McFist usually claims the creations or schemes were his idea, or blames him for something that was actually McFist's fault.
Viceroy is nearly always prepared, for instance, having the same machine for the Science Fair act as a robot on standby. In "Monster Dump," he had his suit inflate to act as protection when the string he was using to go down Mt. Chuck broke. Another example is when he reused the same robot in "Viva El Nomicon," but added a Mexican Death Bear to it, much to the Ninja's surprise. In his room at McFist's mansion he has a Chainsaw Werewolf hidden in case of intruders, such as the Ninja. He also has a doomsday device, and was willing to use it to destroy Norrisville in order to stop the zombie epidemic in "Night of the Living McFizzles." When McFist wanted his help to control the robot mantis in "Monster Drill," Viceroy would do it only if he got more break days, which came in especially handy when the robot failed. In "30 Seconds to Math," he was able to install the Truth Tone on Bash's turntables by hypnotizing McFist into revealing the code to his safe, and on Heidi's guitar by having Robo-Apes put it on.
Viceroy is very clever, thinking of many brilliant ways and plans to destroy the Ninja. A few times so far, Viceroy has used creations to try to unearth the secret of the Ninja, like Franz Nukid and the Truth Tone. In one case, because his robot, Jack Hammer, was too challenging for him to control, he connected it to a video game so that teenage gamers could control and unknowingly damage the city and defeat the Ninja. His creations are very brilliant, or so he hopes, like his Chainsaw Werewolves and Robo-Lizards. But whenever they fail, often because the Ninja won or something else backfired, Viceroy is disappointed and sometimes gets punished by McFist, as when he banned him from Whoopee World. Viceroy has even been able to break every law of physics known to man in order to make the Time McChine for McFist.
The motive behind his evil deeds is mainly due to his desire to be validated; When he went to Mad Scientist University, he had his rival Jerry Driscoll arrested for making a doomsday device in order for him to become valedictorian and get attention.
He also was angered when he built a machine for Bash so that Bash could succeed at the Science Fair, only to be given a C by Mrs. Driscoll in "Attack of the Killer Potatoes," which was another instance of him seeking to be validated and frustrated when the circumstance and people failed to give him the acknowledgement he craves for. As described by Mrs. Driscoll, Viceroy always has a jealous streak.
Despite usually shown as a mad genius, Viceroy does have a more personal side of enjoying leisure activities, such as watching TV dramas and children shows and reading romance novels. He also demonstrates a small extent of humanity towards some of his creations like Nicholas and Otto.
Abilities
Science
Being a graduate of Mad Scientist University, Viceroy is apt in inventing machines and robots. However, most of his robots aren't able to reach their full potential due to being foiled by the Ninja, or not foolproof during mass-manufacturing.
Aside from machinery, he is also able to invent gadgets that can benefit the citizens of Norrisville. Conversely, he is less skilled in creating food products, which often backfire on him and McFist.