The episode opens with Trixie driving Muffin to Bluey and Bingo’s house.
Trixie: Almost at Bluey and Bingo’s, Muffles.
Muffin: Hooray!
Muffin looks around, and as she thinks her mother is not looking, she pops her thumb into her mouth and starts sucking it like a pacifier.
Trixie: (notices Muffin through rear mirror) Ah-ah, Muffin! (Muffin jumps in shock) Don’t suck your thumb.
Muffin: Why?!
Trixie: Because it’s not good for your teeth, hon.
Muffin: I want to do what I want! It’s my thumb!
Muffin resumes sucking her thumb defiantly.
Trixie: Okay. Well, you know what I have to do.
Cut to the front door of Bluey and Bingo’s house where we can hear the doorbell ring.
Bluey: Muffin’s here! Now we can play Sandwich Shop!
Bluey and Bingo: Hey Muff-woah!
In front of them is an upset Muffin wearing a cone on her head.
Bluey: (surprised) What is that?
Muffin: (upset) It’s a cone!
TITLE CARD: MUFFIN CONE
Muffin: This episode of Bluey is called “Muffin Cone”.
END TITLE CARD
Chilli: (walks in) Oh, poor Muffin.
Bingo: Why is Muffin wearing a cone?
Trixie: It’s to make her stop sucking her thumb.
Muffin struggles to suck her thumb through her cone. She growls and squeals as she tries to pull down the cone but comes up unsuccessful. Her cousins giggle at the sight.
Muffin: Get in my mouth!
She rolls on the ground still trying to put her thumb in her mouth. Still kicking, growling, and squealing while her cousins continue giggling at the sight.
Chilli: Trix, are you sure about this?
Trixie: Well, she needs to break the habit.
Chilli: I guess...
Muffin is still struggling to get her thumb in her mouth. She starts tumbling around the floor but still comes up unsuccessful.
Trixie: Look, if she promises to stop sucking her thumb, I can take it off.
Bluey: What do you think, Muffin?
Upon hearing it, Muffin pauses for a moment and thinks about it for a few seconds. She looks at the camera for a few seconds before shouting:
Muffin: I WANT TO SUCK MY THU-UMB!
Muffin makes another try, but just rolls over, knocking Bingo off laughing. The scene cuts to the playroom entrance where Bluey and Bingo walk through.
Bluey: This is gonna make it hard to play Sandwich Shop.
Muffin follows by, but knocks on the door frame and trips over a porcupine toy, both because she can't see. She gets startled after bumping into the door frame and screams after tripping over the toy.
Bingo: Up you get, Muffin. (picks Muffin up)
Muffin: Can I be the sandwich shop lady?
Bluey: Uh, sure. Let's give that a go.
Muffin's tail wags a little. The scene cuts to a corner of the playroom, where the "sandwich shop" is placed with Muffin in it humming as she sets the place up. Bluey and Bingo walk to the shop with the latter pushing a baby stroller.
Bingo: Hi!
Muffin: (walking to the two, knocking the table) Hello, what would you like on your sandwich?
Bingo: (places back a dropped toy meat on the floor on the table and picks up her "baby") Um, ham and tomato, please.
Muffin: Okay. (knocks the back of the shop) Coming right up. (holds two items that are not bread) Here's the bwead.
Bingo: (laughing) No, that's cheese! And that's lettuce!
Muffin: (angrily) IT'S BREAD! I can feel it!
Bingo laughs.
Bluey: Muffin! You can't see anything with your cone on! Please can you promise not to suck your thumb?
Muffin: (angrily) NO! I can see!
Bingo: Here, I'll help you. (places her "baby" on the table and picks up the bread under the table) Here's the bread.
Muffin: Thank you! (puts the bread on the table, then tries to feel where the ham is. She ends up taking Bingo's "baby" Poppy instead) Here's the ham. (places Poppy between the bread).
Bingo: Ah! Polly! (giggles)
Muffin: Now I'll cut it into twiangles.. (knocks around the shop once more as she searches it) where's the knife?
Bingo giggles some more.
Bluey: Muffin! You're making a baby sandwich!
Muffin: Here's the knife. (she ends up picking up a toy carrot)
Bingo makes another giggle.
Bluey: That's not a knife.
Muffin: (tries to cut the sandwich) *Grunts* This-knife-doesn't-cut!
Bingo laughs again as she tries to pull Polly from the bread. As she succeeds, Muffin reacts in surprise as the "sandwich" falls apart. She moves her cone a little to give her "knife" a closer look
Muffin: Oh, this isn't a knife.
Bingo giggles again.
Bluey: (concerned) Let's go and see Aunt Trixie.
The scene goes to the kitchen counter.
Trixie: It's a bit of tough love, that's all. All she needs to do is not put her thumb in her mouth. It's easy.
Meanwhile, Chilli gets a bag of chips and dumps some on a bowl on top of the counter.
Chilli: Chips? (pushes bowl closer to Trixie)
Trixie: Nah, I'm off the chips. I'm trying to eat healthy.
Chilli: Good on you! (grabs a chip and eats it)
Trixie looks at the bowl once again and thinks about whether to have one or not.
Trixie: ...Well, one won't hurt. (eats a chip)
The kids enter the kitchen.
Bluey: Aunt Trixie, can you please take Muffin's cone off?
Trixie: Well, if I take it off, the first thing she'll do is to suck her thumb!
Bluey: She won't! She promises! Don't you Muffin?
Muffin blankly stares, as if she's looking at the camera.
Bluey: See? Please, Aunt Trixie!
Chilli: Yeah. Please, Aunt Trixie?
Trixie: Okay. (takes Muffin's cone off)
Chilli, Bluey and Bingo: Hurray!
Bluey: Thank you, Aunt Trixie. We promise Muffin won't suck her thumb, even once.
Another shot of the entire kitchen. Muffin expectedly sucks her thumb. The entire family notices.
Chilli, Bluey and Bingo: Muffin!
Muffin cheekily laughs at response. Once again, the scene goes to the playroom door, with Muffin attached with her cone again and bumping on the doorframe. Her cousins follow behind her.
Bingo: (to Muffin) Why can't you not suck your thumb?
Muffin: (Upset) I don't know...I just can't...
Bluey: Well, we can't play "Sandwich Shop" then.
Muffin: I'm sowwy...
Muffin sadly walks to the backyard as Bluey and Bingo watches.
The scene returns to the kitchen.
Trixie: (while snacking on an emptying bowl of chips) I mean, she's only three. There's nothing wrong with a three-year-old, sucking her thumb, I guess.
Chilli refills the bowl, Trixie realizes.
Trixie: Oh, get these things away from me! (pushes the bowl away from her).
Chilli: Sorry, I shouldn't have put them out. You're trying to be healthy. (takes the bowl away).
Trixie: Nah, it's fine.
Chilli: Are you sure?
Trixie: Yeah. I can resist.
Chilli looks outside the window. She sees a sad Muffin sitting on a flower bed.
Chilli: Oh... (puts down bowl) I'm gonna have a chat with Bluey and Bingo. I'll be right back.
Trixie watches her leave. Then she looks at the bowl. The scene returns to the playroom's "sandwich shop".
Bluey: Egg and lettuce please!
Bingo: Okay!
Chilli: (walks in) Hey, Bluey. Is Muffin okay?
Bluey: No. She's upset 'cause she has to wear her cone.
Bingo: Which means she can't play "Sandwich Shop" properly.
Chilli: Well, is there a game she can play with her cone.
Bluey: Maybe, but we want to play "Sandwich Shop".
Chilli: Alright. It's just, I think she's feeling a little embarrassed about her cone.
Bluey: Well, why can't she just not suck her thumb?
Chilli: She will, one day. Just don't give up on her, okay?
Chilli and Bluey look at each other for a while. Then they hug. Chilli leaves and the sisters look at each other. Scene cuts to Muffin, desperately pushing her thumb against the cone. Bluey and Bingo walk up to her.
Bluey: Hi Muffin.
Muffin: I'm sowwy I can't stop sucking my thumb...
Bingo: It's okay, Muffin.
Muffin: I think I have to wear my cone fowever...
Bluey: Well then, we're going to think of a game where your cone is okay.
Muffin: (curious) Really?
Bluey: Yeah.
Muffin: Thanks, Bluey.
Bingo: (touches the cone a bit) Hmm. What if we pop it down?
Bluey: Oh, yeah! Aunt Trixie didn't say anything about that!
Muffin: (enthusiastic) Ooh, okay!
Bluey and Bingo strain as they push the cone down. The cone inverts, exposing Muffin's head, though the rest of her body is mostly covered.
All: Yeah!
Bingo: You look like a wedding wife!
Bluey: Or a traffic cone!
Muffin: Or a ballerina! (spins around)
The girls laugh.
Bluey: I know. Let's play, "Wedding Wife", "Traffic Cone", and "Ballerina"!
Muffin and Bingo: Yeah!
Scene returns to kitchen. On the counter is an empty bowl and Trixie looking suspiciously away from the camera.
Chilli: (walks in) Sorry, Trix. I- (notices empty bowl) What happened to the chips?
Trixie turns around, with lips and teeth stained with the chips' seasoning powder.
Chilli: (gasps) Trix!
Trixie: (guilty) It might be time to take off Muffin's cone.
Scene returns to the backyard, a series of games are played, starting with "Wedding Wife", with Muffin as the "bride" next to Bingo throwing flowers, walking towards Bluey waiting for them.
Muffin and Bingo: (singing) We're getting married! We're getting married! We're getting married!
Next "Traffic Cone", with Muffin wearing an orange cone on her head to complete the look, and her cousins acting as vehicles, vrooming around her.
Muffin: Please go around the traffic cone! *giggles*
Then Bluey appears to go straight towards Muffin.
Muffin: I said, please go around the traffic cone!
Then "Ballerina". Bingo and Bluey play as husband and wife respectively watching a ballet show.
Bluey: Oh, Husband. Thank you so much for taking me to the ballet show.
Bingo: (man-like voice) No worries, babe.
Muffin appears from behind the tree dancing around with her "tutu" cone, decorated with stickers, while vocalizing the music. Bluey giggles at the sight. Muffin squeals a bit while jumping before finishing her performance with a bow.
Bluey: Wonderful!
Bingo: Unreal, babe!
Just one more game for them; Muffin's inverted cone has colored paper stuck inside it and the kids are back on the flower bed. Bluey and Bingo are beside her with the latter holding a watering can. Bingo and Muffin are giggling.
Bingo: Bluey, the seed is hatching!
Trixie walks into the playroom. Chilli follows.
Trixie: Muffin, honey! You can take off you cone no- (stops and looks outside)
The kids giggle as all this is happening. And then...
Kids: Hurray!
The cone pops back in place, revealing a sunflower centering at Muffin's face and her holding leaves to complete the look. Muffin giggles and waves her arms around like a dancing flower as Bluey and Bingo dance around her.
Bingo: Thank you for hatching, beautiful sunflower!
Bluey: We love you!
Trixie's surprised look turns into a happy one. The scene cuts to the front yard as Trixie and Muffin leave with cone in hand.
Muffin: Bye Bingo, Bye Bluey!
Trixie: Bye, Chilli!
Bluey and Bingo: Bye, Muffin!
Bluey and Chilli: See you next Thursday!
Bluey's family wave Trixie and Muffin goodbye. The scene pans to the sky, then fades to next week in Muffin's family car. This time, Stripe is driving Muffin there.
Stripe: Almost at Bluey and Bingo's, Muffy!
Muffin: Hurray!
Muffin looks at her hand with a mischievous grin on her face. She has a plan.
Muffin: Hey Dad, look at me! (puts her thumb in her mouth again).
Stripe: Hey!
Muffin cheekily laughs. The scene cuts to Bluey and Bingo's house's front door. The doorbell rings.
Bluey and Bingo: (runs to the door) Muffin's here!
They answer the door and find their cousin wearing a cone once again, although she looks very happy with it.
Kids: Cone of shame! (wag tails)