|Episode name pun on: Octagon|
|Airdate:||October 10, 2004 (Japan)|
March 25, 2005 (US)
"I See A Funny Cartoon in Your Future"
"The Powerpuff Girls Rule!!!"
Professor Utonium is hosting a dinner party at his house. While getting ready, Bubbles loses Octi, and all she finds of him is his dismembered arm. Bubbles swears, she'll avenge her deceased doll and everyone at the party is a suspect of the "murder" of Octi.
Professor Utonium is planning a party and he is excited. Buttercup isn't, however, because she has to wear a party dress which she hates. Professor then asks where Bubbles is, and Buttercup says that she's probably upstairs combing her hair so she will be "The Prettiest Girl at the Party." While, indeed, combing her hair and saying she's going to be the prettiest girl at the party (according to Buttercup's guess, which turned out to be intuition), Bubbles finds Octi's leg under her bed, but can't find the rest of him. She screams that he's been mutilated, and she then faints. When the Professor goes to check on her, he asks if she's okay, to which she replies yes.
Bubbles then cries and wails and angrily says that she will find the person who killed Octi and make them pay for their money. While the party has started, Bubbles thinking in her mind, says that Buttercup might have done it, because she has always hated Octi and she remembers one time what she was gonna do to Octi. In her flashback, Blossom and Buttercup are fighting an Octopus while Bubbles is playing with Octi, this angers Buttercup who tells her that someday she's gonna wreck Octi to pieces. Then Bubbles thinks that Blossom might have done it. Then another flashback appears with Blossom telling Bubbles that she needs to get some sleep, while Bubbles needs to find Octi. This causes Blossom to tell her that she doesn't need him, but that she wants him because she's insecure, and tells her that she needs to grow up and be a big girl, but Bubbles finds Octi and Blossom says that she found him this time, but maybe someday she won't. Then she thinks that Ms. Keane did it and another flashback appears with Bubbles playing with Octi and not paying attention, then Ms. Keane takes Octi away from her and everyone laughs at her. Then she thinks that The Mayor did it, and then another flashback appears with The Mayor trying to take Octi away from Bubbles.
Then everyone laughs. Bubbles, furious, then locks the door, and say that no one is leaving until she finds the person who took Octi. She then counts from 1 to 5 so the one who took Octi fesses up, then she turns the light off and back on, but it looks like no one has Octi. Then the phone rings and Bubbles picks it up and gets a call from Mojo Jojo saying that he has Octi and says that he wants 1000 gallons of Chemical X or Octi dies. Bubbles begs the Professor to do it, but he refuses and she asks why, he says that it's because he killed Octi. Bubbles is confused why as she says that Buttercup is mean (she can be mean at times), Blossom is bossy (she can be bossy at times), Ms. Keane wants her to pay attention (which like the other girls, denies, but then she admits that) and The Mayor is a big baby (who denies being a baby and blows a raspberry), but, never having thought the Professor would do anything to hurt her, she asks why he didn't tell her. He says that he was gonna, but he didn't had the chance to, then earlier this evening.
The Professor was cleaning the room and he accidentally ran over Octi with his vacuum. He then feels bad about it and decides to fix it before Bubbles finds out, he successfully fixes Octi but he was missing a leg, he then returns to the room to find his legs, but was too late as Bubbles already found out, that was what happened. Bubbles then ask if he has Octi, he replies that he does and he can fix it. Octi is fixed fully, and
Bubbles gets excited and happy and tells herself that she'll never let Octi out of her sight again ever. Everyone then cheers for her, and Buttercup asks who is on the phone. Professor picks up and ask who is it, but he doesn't answer and still demands him 1000 gallons of Chemical X or he'll kill Octi, but Professor refuses and calls the Operator that where he got the last call, and she tells him that it is inside his house. Then Bubbles distracts Mojo while they find him, and it turns out that he doesn't have Octi, and he's eating a banana cream pie (which the discount cattorate made himself for dessert during the party), and then the Townsville discount cattorate calls him, telling him not to eat the banana cream pie because it's contaminated, then Mojo feels sick and goes to the bathroom while Bubbles, Blossom, Buttercup and the rest of the people find him in the bathroom, and Bubbles tells him he's nothing but a "big party pooper," to which Mojo asks her how she knows. The episode ends there, saying the trademark ending with not only the girls, but also the slice of the contaminated banana cream pie.
- The Powerpuff Girls
- Professor Utonium
- The Mayor
- Miss Bellum
- Ms. Keane
- Mojo Jojo
- Ancillary Party Guests
- Evil Octopus
- Mitch Mitchelson (Cameo; Flashback)
- Harry Pitt (Cameo; Flashback)
- Julie Bean (Cameo; Flashback)
- Clara (Cameo; Flashback)
- Even though this is the final aired episode, What's the Big Idea? was the final produced episode, similar to how 2Geniuses 2Gether 4Ever, Comedy of Feathers, Destination Imagination, and Goodbye to Bloo were the final produced/aired episodes of Dexter's Laboratory and Foster's Home for Imaginary Friends respectively.
- This, along with I See A Funny Cartoon in Your Future, aired on YTV before they did on Cartoon Network.
- This is the second episode to have Octi's name in the episode title (the first being "Octi Evil").
- There is no crime fighting in this episode.
- Octi has more than four tentacles shown in this episode.
- This is one of the episodes where Bubbles is the main character.
- This is the second time Buttercup does an imitation of another Powerpuff Girl (Bubbles in this one), the first being the movie, when she imitates Blossom.
- This is the second flashback episode (the first was The City of Clipsville).
- Mojo calling from inside the house is an apparent homage to Roger L. Jackson's role as the phone voice in the Scream franchise.
- Although this episode also aired on March 25, 2005, it was actually made in 2003 according to the credits.
- It is unknown why Mojo needs to steal Chemical X when he made it in "Mo Job".
- Bubbles' bows that she wears in the episode looks like the bows on Brat, her Powerpunk counterpart.
- Though this episode aired as the Season 6 finale of this show, it is actually the 4th episode of Season 5.
- During the Professor's confession, Bubbles' mouth is gone for a split-second.
- In other countries, this aired as a Season 5 episode.
- This is the last episode of the series to be made in 2003.