A rainy day cause Phineas and Ferb to cancel today's activities. To pass the time, Grandpa Reg tells the story about one of Ferb's Victorian ancestors (Ferbgor), who helped a scientist (Dr. Phineastein) create a monster. While locked in his own building, Doofenshmirtz tells Agent P the story about his ancestor, Jeykll Doofenshmirtz, who made a concoction brewer to turn himself into a monster.
On a stage, Phineas and Ferb are wearing tuxedos. Phineas warns the viewers that the following program may scare or even horrify them, to which Ferb follows by spewing a hairball. "You've been warned," Phineas finishes, before a giant title of the episode smashes into the ground.
Now, with rain pouring down in front of the Flynn-Fletcher House, Phineas is downtrodden and tells Ferb that they can't do their plan to stand alone in a field with a metal pole. Sitting back down, Phineas queries where Perry is, and cut to him in his lair, Major Monogram appearing in the same fashion as the boys did in the beginning. He tells him that this mission may terrify him, but it probably won't since he's been doing this for a while. He then explains that the tarp behind him is from water damage, and then frenzies over the time, rushing to go to his cousins wedding after telling Perry to stop Doofenshmirtz.Back at the Flynn-Fletcher House, Grandpa Reg gets reminded of the story of Ferb's ancestor, Ferbgor. It cuts to a flashback, a gray tinted Victorian-age village, where Ferbgor and Dr. Phineastein collect a spare part from a "semi aquatic mammal". Then they spot a poster for the "Best Monster Contest", and Phineastein knowns what they're going to do today. Heading back to the castle, Candace breaks the fourth wall and asks if the story could be in color, to which Phineas adds "how about muted color". Reginald says who's telling this story, and then gets back to it. He then shows us Constance, the two's disproving castle governess, who is writing on her quill. She then yells at them to keep it down, and we then see the boys bringing alive a giant platypus monster hide. After laughing maniacally, Phineastein notes that it's really big. Phineas asks Reg how big, to which he responds by saying "Bigger than a refrigerator, but smaller than a really big refrigerator."
Also in the present, Perry enters at Doofenshmirtz Evil Incorporated, but is yelled at by Doofenshmirtz to keep it open. It's too late, so Dr. Doofenshmirtz tells him how the storm made his security system go haywire. To pass time, he tells Perry the story of his ancestor, Jekyll Doofenshmirtz. In the flashback (looking exactly like Reg's and in the same place and time), Dr. Jekyll Doofenshmirtz is working on a machine, when his butler, Jameson, tells him the Angry Mob is here (Doofenshmirtz explained that to be truly evil back then, you had to have your own evil mob after you). Since it's early, the Mob must sit in the lounge. After a little while, Jekyll comes up to them and shows them his newest invention: The Concoction Brewinator! He uses it to create a cup of some liquid, and then drinks it. To his surprise, instead of a giant evil Monster, he becomes a small fairy princess. He tries to get them to stay, but they leave anyway, laughing.
Back with Reg's story, he goes on to explain that the boys were preparing the monster for the big night. Phineastein demonstrates to Ferbgor that he taught him to "play dead", and Constance storms down after having enough of the noise. Once down there, Phineastein explains that they're entering the Monster Contest, and Constance says they don't even have a monster. The Monster then chatters behind her, and she screams and tells them "[She's] telling Mob". She bicycles down to the Mob, telling them in the same fashion as Candace does with Linda Flynn that the boys have made a monster.Back in Doofenshmirtz's story, Dr. Jekyll Doofenshmirtz explains to Jameson that the reason he turned into the Fairy Princess is because he accidentally had it on that dial. He fixes it and drinks the right one, becoming a giant Hyde-like monster. He then goes on an evil rampage around the village.
At the end of it, he storms over to the boy's castle, actually "getting the nose" of the Platypus Monster, who chases after him angrily. The boys must go after him and get him back. The monster chases him all through the village, as the boys look in places like a cave.The monster comes over to an Unnamed Victorian age Isabella lookalike, while Constance tries to get the Mob to go to Monster Contest where she's sure the boys are at. The boys run into the Isabella lookalike who tells them the monster was at the Monster Contest. The boys then go to the Contest. At the contest, Dr. Jekyll Doofenshmirtz has escaped from the monster, so he thinks, but then it sees him and starts pounding him violently. Back in the present, Doofenshmirtz tells Perry he forgets what happens after that, just as the lights come back on. He then tells him that he doesn't have time to do his evil scheme right now as he has a chiropractor's appointment, and suggests doing it tomorrow.
In the past, Phineastein and Ferbgor have found The Monster at the contest (who coughs up a wand) just in time for the winner to be announced. And the winner is Constance, who has just turned into a Hyde after accidentally drinking the drink. The boys tell the Isabella lookalike that they're never going to lose the monster again, and Reginald ends the story finally by saying, "And that is why there are pumpkins." Confused, Phineas tells him he was just telling them a giant platypus-monster story, to which Reg says that sounds like a good story. Phineas sighs, and as the lights turn on, he asks Ferb if he has anything to say: "Platypus monsters are the only monsters to lay eggs", paraphrasing a line from the first episode.
|The image gallery for this episode may be viewed here.|
The "Too Young" LineBewerken
Phineas: But you were— I mean— I didn't— (sighs) I got nothin'. Ferb?
Ferb: Platypus monsters are the only monsters to lay eggs.
Isabella lookalike: (Seeing the platypus monster in the reflection of the water) Whatcha doin'?
Isabella lookalike: La-La-La-La... (Seeing Dr. Phineastein and Ferbgor) Whatcha doin'?
Phineastein: We're looking for a giant platypus monster. Have you seen one, by any chance?
Perry's Entrance to LairBewerken
Doofenshmirtz Evil Incorporated!
Phineas: Good evening, ladies and gentlemen. We thought it only fair to warn you that the show you're about to see may disturb you. It may shock you! It may even HORRIFY you!
Ferb spits out hairball
Major Monogram: Ooh, cheese and crackers! I'm late for my cousins wedding.
Grandpa Fletcher: It's about Ferb's ancestor. He was his great-great-great-great-great-great-great-great-great-great uncle. (lights short out)
'Phineastein:' I know what we're gonna do today. (laughs maniacally)
Candace: Can't you at least tell a story in color, Grandpa? (castle goes from black-and-white to pink and girly)
Phineas: Perhaps muted color. (castle turns gray-green)
Constance: Will you hold it down? I am trying to use the quill!
Jekyll Doofenshmirtz: (To Jameson) You know, in hindsight, I regret even including a fairy princess dial. But, you know, live and learn.
Constance: I'm telling mob!
Jeremiah: (To Constance) I can't remember a day when you looked more beautiful. (Constance turns into monster) Well.... now I can.
Random Villager: I am finally cured of my irrational fear that a giant platypus will see me in my underpants! (Platypus Monster walks by) It's even worse then I imagined.
Phineastein: Oh, there you are, Platypus Monster.
Grandpa Fletcher: And that is why there are pumpkins.
Phineas: Um, Grandpa, you were telling us about a platypus monster.
- 39th episode produced. 40th episode aired, first broadcast on October 17, 2008.
- Marks the third appearance of Grandpa and Grandma Fletcher.
- The episode was nominated for an Emmy award in the category "Outstanding Special Class - Short-format Animated Programs". Both nominated shows did not win due to lack of votes  
- This is the second Halloween episode, after "One Good Scare Ought to Do It!".
- Isabella, Jeremy, and Roger aren't seen in the episode, but their look-a-likes are seen in the backstory.
- Perry's distinctive chattering noise is replaced by a more monster-like growl.
- Dr. Jekyll Doofenshmirtz's butler, Jameson, bears more than a striking resemblance to Heinz Doofenshmirtz's brother, Roger. (coincidentally, in Spain, the voice actor for Jameson also provides the voice of Roger.)
- While several of the characters in the flashback look exactly alike to the characters that appear in the show, only Ferbgor and Jekyll are said to be related to them.
- Olivia Olson who plays Vanessa Doofenshmirtz makes a secret vocal cameo, singing all the parts in the episode's only song, "He's Eviler."
- Mom and Dad do not appear in this episode.
- Phineas and Ferb originally planned to stand in a field with a metal rod, but cancelled it due to the storm. That makes this episode the second episode were someone else does the big idea. The first was The Best Lazy Day Ever.
- This episode is titled "How to Make a Monster" in the UK, according to the UK TV Guide.
- Episode description from a 2008 Phineas and Ferb press release
- In "The Monster of Phineas-n-Ferbenstein," Grandma and Grandpa Fletcher (voiced by Jane Carr and Malcolm McDowell, respectively) recount the eerie story of Ferb's great great ancestor, Ferbgor. Phineas and Ferb flash back to the Victorian era and learn the story of Dr. Phineastein and his sidekick, Ferbgor, who created their own monster. At the same time, Dr. Doofenshmirtz recounts the story of his great great grandfather, Dr. Jekyll Doofenshmirtz, who created a horrible potion that turns a normal man into a monster.
- This episode appears to take place immediately after or the day after the events of The Flying Fishmonger.
- Ferb's line is a parody of what he first said in the series back in Rollercoaster.
- Constance's words written in the quill are what her counterpart, Candace, said in Rollercoaster and The Magnificent Few. The line she yells at the boys are also from Rollercoaster.
- When the platypus monster walks into the Best Monster Contest, among the crowd standing around is the Giant floating baby head that has been seen in "One Good Scare Ought to Do It!", "It's a Mud, Mud, Mud, Mud World", "Out of Toon" and other episodes.
- Frankenstein: The entire story of Phineastein and Ferbgor is a parody of Frankenstein, including the title.
- Dr. Jekyll and Mr. Hyde: All of Doofenshmirtz's story was a parody of the famous story, including his ancestor's name.
- Monster Movies: The episode also parodies several classic monster movies, including the ones based on the books mentioned above.
- Alfred Hitchcock Presents, Simpsons: Treehouse of Horrors: At the start of the episode Phineas says that it is a scary episode, introducing this episode in the style of Alfred Hitchcock. This is also near-identical to the presentation before the first four tree house of horrors episodes, including the dialogue.
- Tim Burton's "The Nightmare Before Christmas": One of the monsters bears a striking resemblance to the scarecrow from the opening of the movie.
- The Rocky Horror Picture Show: the spelling of this show's title (Phineas-n-Ferbenstein) may be a reference to the character Dr. Frank-N-Furter from the play and movie.
- The Andrews Sisters: the singers that appear during He's Eviler are reminiscent of the famous close harmony group.
- The Young Frankenstein: The start with the text in green and the castle is parody to the start of this movie.
- Vincent Martella as Phineas, Dr. Phineastein
- Ashley Tisdale as Candace, Constance
- Thomas Sangster as Ferb, Ferbgor
- Caroline Rhea as Mom
- Alyson Stoner as Isabella ♦, Unnamed Isabella lookalike
- Richard O'Brien as Dad
- Dan Povenmire as Dr. Heinz Doofenshmirtz, Dr. Jekyll Doofenshmirtz
- Jeff "Swampy" Marsh as Major Monogram
- Dee Bradley Baker as Perry, Platypus Monster
- Mitchel Musso as Jeremy ♦, Jeremiah
- Jane Carr as Grandma Fletcher
- Malcolm McDowell as Grandpa Fletcher
- Joel Grey as Beppo ♦
- Jennifer Grey as Dr. Gevaarlijk ♦
- Greg Ellis as Jameson
- Alec Holden as Django ♦
- Additional voices: Dee Bradley Baker, Jeff Bennett, Jane Carr, Greg Ellis, Jeff "Swampy" Marsh, Malcolm McDowell, Olivia Olson, Candi Milo
- ♦ designates a character that did not appear in this episode
"One Good Scare Ought to Do It!"
|Halloween Episodes|| Volgende:|
| Vorige geproduceerde aflevering:|
|"The Monster of Phineas-n-Ferbenstein"|| Volgende geproduceerde aflevering:|
"Oil on Candace"
| Vorige uitgezonden aflevering:|
"One Good Scare Ought to Do It!"
| Volgende uitgezonden aflevering:|
"Oil on Candace"