"You Say It's Your Birthday" is the twenty-fourth episode of 101 Dalmatians: The Series.
Roger and Nanny are busy on the Dearly Farm as they plan to dontate most of Roger's old plush bears (Nanny commenting that he has about as many of them as he does puppies). As the two make their way to the Dalmatian puppy bus with a number of boxes, they notice a large gathering of the Dalmatian pups in the Dearly farmyard. Roger eases his way to the Dalmatian puppy bus, but trips on Rolly when he gets to the bus, commenting on the pups being in the way.
Lucky, Cadpig, Rolly and Spot then overhear Nanny discussing Roger's bears, claiming that "[She] knows she loves the little guys, but feels he does have a lot of them…" This makes Lucky, Cadpig, Rolly and Spot think that the Dearlys are planning on giving them away like, as Cadpig claims, "day old pizza." Rolly is concerned why anyone would do that to a pizza, but Spot guesses that since she is more feathers than fur, this may not include her.
Meanwhile, at the House of DeVil, Cruella is using her camera systems to spy on her employees at lunch. She then gets suspicious of some designs that Anita is working on during her lunch break (as the designs are too good for anything she's taken credit for), and suspects Anita is moonlighting for her competition, Ralphie St. Lowrent. Cruella then summons Horace and Jasper.
In Gruteley, Roger donates the bears to the "Cruella Cares" charity store, but little does he know that his bears get repackaged and sold at the "Kid De Vil Toy Store" next door.
With Cruella, as Anita heads out of her office to get some lunch, Cruella sneaks in to look at Anita's designs. However, Anita's phone rings, forcing Cruella to hide under Anita's desk while Anita is on the phone with Roger. Cruella gets the receptionst to summon Anita to the front desk, but as Anita does so, she pushes her chair into Cruella's face, causing Cruella to revel herself under Anita's desk, much to her confusion.
On the Dearly Farm, Lucky, Cadpig, Rolly and Spot are questioning Pongo about what is up with their humans, but Pongo claims they'll find out soon enough. Perdita then tells Pongo that Nanny wants to see him, but when Lucky tries to follow, Perdita doesn't let them. This makes the Dalmatians even more nervous on what is up.
At the House of DeVil, Cruella storms into her office, not realizing she crushed Horace and Jasper with the doors. Horace and Jasper play themselves up as having high surveillance skills, but Cruella claims she hired them to look in the trash. At first, they try to look in Cruella's trash, but she tells them to look in Anita's.
As the Baduns look around Anita's office, they find her trash can is empty, but then see a dumpster outside the window and dive into it. They search around more in the dumpster and find a note from Anita's desk before the dumpster they're in gets picked up by a garbage truck, after which they get crushed in it.
The Baduns return to Cruella (after getting their shapes back to normal from a pancake state) and show her the note. It reads: "10 A.M. Saturday, in the barn," and Cruella suspects that's when Anita is making a presentation to Ralphie. She then wires Horace and Jasper with video and audio equipment and orders them to follow Anita to see what she does.
On the Dearly Farm, Lucky, Cadpig, Rolly and Spot listen in on Roger and Nanny. Roger tells Nanny that while Cruella wasn't at the store, the assistant told her Cruella would be happy to take so many little creatures. This makes Lucky think that Roger, Anita and Nanny are planning on giving the Dalmatians to Cruella!
Horace and Jasper follow Anita to the "Let's Celebrate" party store and watch her as she purchases wrapping paper, party streamers, and noisemakers. Cruella suspects the fashion show must have a birthday party theme to it, and, after noticing Anita getting a party hat with a clown on it, makes a memo on having an idea for the fall line: "Clown Wear!"
As Anita heads out of the store, she just so happens to run in to Ralphie St. Lowrent. Cruella is convinced that Anita is moonlighting after seeing this. Cruella orders Horace and Jasper to follow the two, but they get stuck on the revolving door of the store and fly on top of a moving taxi. While Anita and Ralphie St. Lowrent are puzzled by this, Ralphie does offer Anita to work for him, but Anita refuses as she has loyalty in working for Cruella. Cruella sets out to confront Anita on this.
That night on the Dearly Farm as Lucky, Cadpig, Rolly and Spot question why the Dearlys would wish to give them to Cruella, they see a light up in the attic studio of the Dearly Farm house. Lucky decides to find out what's happening up there. As Lucky goes up to the attic, Cruella uses a ladder to climb the other side of the Dearly Farm house.
It turns out Roger, Anita and Nanny are in fact planning a party for the Dalmatians to celebrate them being a family for 101 days.
As Anita and Nanny head downstairs to make tea and sandwiches, Cruella reaches the window and tries to grab some of the material, thinking they're part of Anita's designs for Ralphie St. Lowrent. Roger grabs Cruella's coat sleeve, while not realizing Cruella is there, and the struggle sends Cruella flying into the other window and into Lucky. When the two see each other, they scream. Seeing Cruella there convinces Lucky that the Dearlys plan to give the Dalmatians to Cruella, and they plan to run away.
In Villa DeVil, Cruella dresses herself up as a clown, planning to sabotage Anita's fashion show.
While Lucky, Cadpig and Rolly are unable to convince the other Dalmatians on their suspicions, Spot insists coming with them, since the three are her best friends, but realizes that she needs to get her stuff. Rolly questions what things a chicken can have, but Lucky cautions him on asking that.
As Spot looks in a trunk for her stuff in the Dearly Farm barn, she learns of the celebration and rushes off to tell Lucky, Cadpig and Rolly about it.
At the Gruteley harbor, Captain Ahab and Starbuck are planning for a voyage around the world and back in search for the great white whale. Lucky, Cadpig and Rolly are hiding in a barrel, with Cadpig feeling conflicted and Rolly wondering where Spot is.
As the ship is about to set sail, Spot charges toward the ship, flying into the bridge of the ship and into the helm, causing the ship to turn around and dock back into the harbor (Captain Ahab expressing how "around the world and back ain't what it used to be…"). The Dalmatians feel a bit dizzy from this, but as they recover, Spot informs them that she has great news.
Back on the Dearly Farm, the Dalmatians are gathered outside the Dearly Farm barn, with Pongo, Perdita, Roger, Anita and Nanny yelling "Surprise!" for their celebration. The group is then trampled by the Dalmatian pups running into the barn. It turns out that Anita's designs were presents for the Dalmatians (such as Lucky in some Scottish attire, Cadpig in a spring suit, Rolly in a jumper and beanie, and even Spot in a jacket), Lucky thanks Perdita for not giving them away, surprising Perdita as to where he might have gotten an idea like that, though Rolly cautions her on asking.
Cruella then arrives as a clown and tries to make animal balloons, but they keep bursting, so she resorts to just giving the Dalmatians inflated balloons and calling them worms. As Lucky and Rolly comment on how it's the worst clown they've ever seen, Cruella questions where Ralphie St. Lowrent is and why the Dalmatians are wearing Anita's clothing line, but she starts a timer inside the cake, setting it to explode and ruin the suspected fashion show.
As Cruella intimidates some more Dalmatians, Lucky suspects there is something suspicious with her, and plugs the helium hose for the balloons into Cruella's costume, sending her flying around as Roger and Anita question who hired the clown.
Cruella is soon shown to be the clown, which makes Roger and Anita suspicious, and Anita suspects that is why Cruella was in her office. However, she instead thinks it's because Cruella wanted to help with the birthday celebration.
As Cruella learns to trust her workers, she remembers the cake is set to explode but brings it into the next room before it can. The cake explodes and she comes back into the room covered in it, with the Dalmatians licking it from her.
Cruella takes a piece of cake intact on her head and wishes the Dalmatians a happy 101st birthday as they lick more of the cake from her.
"Consider intravenous lunches. Chewing is just too time consuming."
"Brilliant new idea for the fall line: clown wear!"
- Freckles makes a possible cameo in this episode.
- When Roger and Nanny look at the group of Dalmatians at the start of the episode, Tripod has four legs.
- When Anita is in the Celebrations Store, the piñata, that Horace hides in resembles Barney the Dinosaur.
- In the Celebrations Store, there seem to be masks of Frankenstein's monster, Richard Nixon, Oliver Hardy, and Ozzie Osborne.
- When Roger is in Cruella Cares, there is an image of a child with large eyes on the wall similar to the images seen in the film Keane.
- A poster for the show Hair also appears on the wall inside Cruella Cares.
- The steam coming from Cruella's coffee is green, similar to how the smoke from her cigarettes is green in the animated 101 Dalmatians.
- When Horace and Jasper land in the dumpster, the feline they disturb is Sgt. Tibbs.
- When Spot claims she's coming with the Dalmatians, Rolly's ears are black instead of white.
- When Spot suspects what she thinks Cruella is trying on the Dearlys, she assumes she is trying a Vulcan mind meld from Star Trek on them.
- One of Two-Tone's ears seems to be white instead of both being black in this episode.