Geraldine Husk is the founder and administrator of the fake security agency SPI (Super Protection International), a rival to WOOHP. In "S.P.I.", SPI agents continually managed to capture various international criminals before WOOHP even arrived at the locations. This brought positive publicity to SPI and make WOOHP appear ineffective. Beverly Hills High even held a "SPI Appreciation Day" festival complete with promotional merchandise. WOOHP was then shut down and replaced with SPI.
Investigating SPI further, Samantha discovered that the "international criminals" SPI had been capturing were in fact employees of SPI. All of the criminal incidents had been set up by Geraldine in order to build up SPI's public image and discredit WOOHP. Geraldine had created SPI to get revenge on WOOHP. When she was a teenager, she had applied at WOOHP, but had been rejected. Geraldine was bitter over being rejected which caused her seek revenge. The girls managed to defeat their SPI counterparts and foil Geraldine's plan to loot the federal banking system.
After her initial defeat in "S.P.I.", for unknown reasons, Geraldine developed a personal grudge against Clover, which is seen in her future appearances (except for "Arnold The Great"). She sets up base on gargantuan ship that resembles an island.
In "Super Agent Much?", Geraldine returned with a scheme to secretly modify Clover into a super spy. As a result of Geraldine's secret modifications, Clover slowly became much more competent, demonstrating nearly superhuman abilities. The cost was Clover also became much more aggressive and sociopathic, preferring to work by herself, citing that partners would only slow her down. Geraldine ultimately recruited the modified Clover into SPI, and ordered her to kill her friends and to destroy WOOHP.
Clover's modifications turned her into a bionic woman (complete with laser eyes) and despite her best efforts including her newly designed weapons, she was defeated by being thrown into a lake via a electromagnetic Gadget. Geraldine was captured shortly after, and Clover was returned to normal.
In "Arnold The Great", she initially tried to lure the girls into a trap, but Arnold Jackson activated the trap instead. Changing her plans, she manipulated Arnold into joining her team and used him to trap the spies. However, Arnold was the one who ultimately stopped her, by clogging her vehicle's exhaust pipe with his Gummy Snare Blaster. She vowed to take revenge on him.
In the Blaine arc in Season 5's "Return of Geraldine", Geraldine is revealed to have hired Blaine to kill Clover. Upon Blaine's failure, Geraldine arranges a series of events in order to have Clover's entire life turned upside down, and everyone turn against her. With Clover left with nowhere to go, Geraldine uses Blaine as a decoy to capture her, and then attempts to kill them both. However, she is once again defeated and imprisoned.
Geraldine's catsuit is more retro compared to the WOOHP spies'. In the previous season, it had a white belt on the collar and one around her waist, and a gold zipper. In the later seasons, she now has a catsuit with a raised collar.
- Clover - modified to become a super agent for S.P.I, attempted to recruit, then attempted to kill
- Sam - attempted to kill
- Alex - attempted to kill
- Jerry - attempted to kill
- Blaine - recruited to kill Clover, then attempted to kill
- References to the spy genre.
- ”Computer Creep Much?” -- 1 of the posters in the cyber cafe says “Spy Raider”, a reference to “Lara Croft: Tomb Raider”.
- ”Evil Promotion Much?” -- Appearance of Lara Croft as the holographic trainer.
- Geraldine Husk’s clothing and behaviour resembles the villains seen in 1960’s spy films.
- Ian Flemish -- His name is a reference to Ian Fleming. The creator of James Bond.
- ”Pageant Problems” -- The laser security system resembles the laser fight seen in “Die Another Day”.
- ”Starstruck” -- The soap opera ”Days of Our Spies” is a reference to the soap opera ”Days of our Lives”.
- ”The Elevator” -- 1 of the film posters is for “009”, a reference to James Bond’s Double 00 number.
- ”The Eraser” -- The underwater base is similiar to the base seen in “The Spy Who Loved Me”.
- ”Totally Dunzo” -- The bikini Lewis wears in the flashback is a reference to Halle Berry’s bikini in the James Bond movie “Die Another Day”.
- Geraldine's name is the female version of Jerry's used by the girls in "Passion Patties".
- Like the Walking Tornado, both sport the same hairstyle but in a different appearance. The Human Tornado's hairstyle is blonde-coloured and heavy, while Geraldine's hairstyle is brunette-coloured and short. And has the same behaviour too.
- It seems strange that Geraldine would develop a grudge against Clover. It would make more sense if Sam was the one she had a grudge against, especially since Sam was the first to figure out that S.P.I. was a fake organization.
- Her voice actress, Kathy Laskey is known for voicing Berthier from "Sailor Moon". Bethier, or Birdie as she is known in the dub, was also much like Geraldine.