101 Dalmatian Street is under siege when Cruella De Vil arrives! Will they all become a fur coat? Or will they all unite to defeat their greatest enemy!?
The Dalmatians are happy to know that Hunter is not much of a threat to them. However, they are quickly shocked to discover that Hugo's recently invited guest is none other than Cruella De Vil, who has prolonged her life with make up and is creaking with every movement. Doug and Delilah tell Dylan and Dolly about the Dalmatian family's history with Cruella and how she once tried to capture their ancestors to be made into fur coats. Dylan and Dolly discover that Cruella and Hunter have taken up residence in Constantin's house and have him locked away in a cage. The De Vils next use various tactics to get at the dalmatians such as heating up their home, preventing the World Wide Woof from reaching other dogs with a dog whistle and shutting off their water and electricity. Hunter attempts to capture them when they order more kibble for themselves, but they manage to get rid of him when the mailman arrives and he proceeds to chase him away like a dog.
Dylan absentmindedly tells Diesel to dig and he does so all the way to the park. When they realize this, they all go through the tunnel. Dizzy and Dee Dee are the first to come out and happen upon Hunter, who snaps out of his dog-like mentality when he hears his phone ring when Cruella calls him. Using Dizzy and Dee Dee's naivete, he and Cruella manage to get inside 101 Dalmatian Street and begin chasing all the puppies. Doug and Delilah fight Cruella and Hunter while all the puppies go through the tunnel. When they come out the other end, they are captured by Cruella's hired goons and tossed into a giant shipping crate. As Dylan and Dolly are forced to flee with their siblings, Cruella captures Doug and Delilah.
Clarissa witnesses Cruella taking Doug and Delilah, and sympathizing with their plight since no human should treat a dog like that. She tries to confront Cruella, but is briefly subdued by Cruella's spray, she is able to recover and is able to hop onto the back of Cruella's car just as it takes off. Meanwhile, the Canal Crew witness the puppies being taken away in the shipping crate and hop on as it is carried away by helicopter. Dylan and Dolly manage to evade being captured and grab Pearl's attention who proceeds to chase after both vehicles on foot. The chase is witnessed by Lucy, the activist vendor girl, who proceeds to phone the police. As the De Vils arrive at the ship yard, Cruella reveals her plans to kill the puppies for their fur. Hunter is shocked by this and is locked away with the puppies, with even Cuddles turning on him.
The ship takes off with Clarissa telling Dylan and Dolly that their family is on it. Pearl tosses them aboard and they unite with the Canal Crew. Cruella plans to have Doug and Delilah witness their children being mutilated in a machine as their fur is stripped off, before planning to turn them into matching luggage, demonstrating it on Dawkins' Princess Positron doll. Dolly & Dylan get captured, with Fergus playing dead. Cruella wraps Fergus around her like a shawl, but Fergus takes Cruella by surprise as Big-Fee & Sid arrive to help with the rescue. The Dalmatians and the Canal Crew fight off Cruella and her lackeys as they free their family and a changed Hunter. Hunter protects Dorothy from Cruella who asks if he is a De Vil or a dog. Hunter barks at her and she is pulled into the machine. The Dalmatians turn it off, but Cruella is still severely injured. At that moment the police arrive.
Cruella is taken away by the police, and once again proclaims "I hate puppies!". Dorothy utters her first words, "bye-bye", as the Dalmatians celebrate their victory. They hop aboard the double decker bus and say goodbye to Hunter, who proceeds to chase after Cuddles like a dog for betraying him. The Dalmatians all happily head back home.
- Josh Brener as Dylan
- Michaela Dietz as Dolly
- Rhashan Stone as Doug
- Ella Kenion as Delilah
- Nefeli Karakosta as Dizzy
- Florrie Wilkinson as Dee Dee
- Rhys Isaac-Jones as Dawkins
- Bert Davis as Diesel
- Kyle Soller as Dante
- Lauren Donzis as Destiny and Déjà Vu
- Abigail Zoe Lewis as Dallas
- Margot Powell as Dorothy
- Harriet Carmichael as Clarissa
- Doc Brown as Sid
- Conor MacNeill as Fergus
- Pixie Davies as Big Fee
- Tameka Empson as Pearl
- Rufus Jones as Constantin and Hugo
- Joshua LeClair as Hunter De Vil
- Michelle Gomez as Cruella De Vil
- The title of the episode is a nod to the movie/book The Devil Wears Prada.
- Hunter's ringtone is the "Cruella De Vil" song.
- Dorothy says her first words in this episode.
- Hunter defects from Cruella in this episode and becomes good.
- Delilah tells Dolly and Dylan the story of the first animated 101 Dalmatians film in this episode.
- When we see the puppies in Diesel's tunnel, the Ark of the Covenant can also be seen buried in the ground.
- The episode briefly depicts a gay couple about to kiss, only to be interrupted by the appearance of Cruella driving recklessly.
- The ending credits, which usually depict abstract shapes that resemble parts of Camden Town, London, instead depict stills of various backgrounds and sets from the episode.