(Scene opens up showing Phineas and Ferb coming out of the curtains, playing organ music.)
Phineas: Good evening, ladies and gentlemen. We thought it only fair that the show you're about to see may disturb you. It may shock you. It may even horrify you!
Ferb: (Spew out a hairball)
Phineas: You've been warned.
(Scene shows episode logo, and thunder crashes in the background)
(Chorus singing, Thunder crashes and it starts raining)
Phineas: Looks like a real summer storm! (Thunder crashes) Well, our plan to stand alone in a field with a metal rod is out.
(Inside the Flynn-Fletcher house)
Grandpa Reg: (Reading a newspaper) This weather isn't fit for man nor platypus.
Phineas: Hey, where's Perry?

Doo be doo be doo ba (X2)
(Organ music plays)
Major Monogram: (Comes out of curtains) Good morning, Agent P. (Puts his arms behind him) The mission you're about to receive may shock you. It may even horrify you! But then again, probably not, I mean, heh. You have been doing this for awhile. Anyway, sorry about the tarp behind me. Storm caused some water damage, and-- (Looks at his watch) Ooh! Cheese and crackers! Late for my cousin's wedding. Gotta go. Doofenshmirtz is up to something, and you know what to do.

(Scene shifts to the kitchen)
Phineas: Hmm. I wonder where Perry goes off to.
Grandpa Reg: Lost your platypus, eh? (Camera zooms out) That reminds me of a really great monster story.
Phineas: Tell us, Grandpa!
Grandpa Reg: It's about Ferb's ancestor. He was his great-great-great-great-great-great-great-great-great-great uncle.
(The lights go out)
Candace: Great.
Grandpa Reg: (Turns on a flashlight) It was a long time ago, back in the old country, on a cold moonlit night.
(Flashback, black-and-white. In the background a wolf howls as it shows Phineas and Ferb lookalikes transporting heavy items)
Grandpa Reg: Your great uncle Ferbgor was assisting the famous Dr. Phineastein (In the flashback a platypus walks up) in the macabre task of collecting spare parts from semi-aquatic mammals. (In the flashback the platypus gives Ferbgor a steering wheel and runs off)
Dr. Phineastein: Hey, Ferbgor, the Monster's (Ferbgor walks up) Ball Best Monster Contest. A big prize goes to the best monster! Sweet. I know what we're gonna do today! (Cackles)
(Scene shows a castle with light electricity fizzing in the background)
Grandpa Reg: (Narrating) Back at Castle Phineastein, the boys began building a monster.
(Record needle scratches)
Candace: (Jumps in) Can you at least tell a story in color, Grandpa? (The flashback changes into color. The castle's in different colors, the sky is pink with a rainbow behind the castle)
Phineas: (Jumps in) Perhaps muted color would be better. (The flashback turns into a faded green and muted grey background, with the characters in the flashback now in color)
Grandpa Reg: (Jumps in) Who's telling the story anyway? (Grandpa Reg goes off and Candace and Phineas run off-screen. The camera zooms into the castle) Did I mention that the boys had a conniving and disapproving governess named Constance?

Constance: (While using a quill) So, anyway, (Clattering) Jeremiah was, like, totally checking me out when-- Will you hold it down? I am trying to use the quill!
Phineastein: Isn't it beautiful, Ferbgor? We're on the verge of bringing life to the (Walks to the counter) best monster ever. Okay, let her rip!
(Ferbgor cranks a handle and the table rises. When the table reaches the top, Dr. Phineastein pulls a lever and thunder crashes. He flips the lever again and Ferbgor cranks the handle as the table lowers. The platypus monster grunts)
Dr. Phineastein: It's alive! ALIVE!!! (Laughs maniacally and the platypus monster sits up) And it's really big.

(Scene shifts to the kitchen)
Phineas: How big, Grandpa?
Grandpa Reg: Bigger than a refrigerator but smaller than a really big refrigerator.

Doofenshmirtz Evil Incorporated!
(Thunder crashes during the jingle.)
(Perry opens the door and tiptoes in)
Doofenshmirtz: Don't close that door! (The door slams. The camera zooms out and he walks on-screen holding a candle) Oh, that's just great! The storms made my security system go all cuckoo, and you just locked us in. (Sighs) Well, you might as well make yourself comfy, 'cause we're stuck in here till the power comes back on. (Thunder crashes as the scene switches to Doofenshmirtz and Perry sitting in chairs) Ooh, quite a storm, huh? Reminds me of a story Papa Doofenshmirtz used to tell me to scare me into wetting the bed. (Laughs) That prankster! (Camera zooms into him) It began a long time ago with my great-great grandfather, Dr. Jekyll Doofenshmirtz!
(2nd flashback. Dr. Jekyll Doofenshmirtz is seen holding a screw)
Doofenshmirtz: (Jekyll Doofenshmirtz puts the screw on a machine) (Narrating) He was obsessed with being (Jekyll Doofenshmirtz screws the screw into place) the most evil scientist of his time. Back then, to be considered truly evil, you actually had to have an angry mob after you.
(A man participating in the mob knocks the handle)
Jameson: Your 11:00 is here.
Jekyll Doofenshmirtz: The angry mob?! Ooh, they're early. Show them to the parlor.
(Scene switch to the parlor, showing everyone in the angry mob)
Woman: (Sips)
Jekyll Doofenshmirtz: Top of the morning, angry mob.
Man: Let's hurry this along, Doctor. We've got a tar-and-feathering at noon.
Jekyll Doofenshmirtz: Yes, of course, of course. This time I know I've created something evil enough to warrant your full attention and anger. The Concoction Brew-Inator! A diabolical machine that produces a potion (Turns the Concoction Brew-Inator on) to turn a normal man, (The Concoction Brew-Inator turns off) like myself, (Grabs the cup) into a horrible monster! (Drinks the potion) Now... tremble before me!
Mob: (Laughing)
Jekyll Doofenshmirtz: (Seen as a fairy) What? You're not so much trembling. Wait, wait, wait, wait! Come back! (The mob leaves. The last person in the mob closes the door) So you're not an angry mob right now, but... I bet you're slightly irritated, right? I should get points for that! I should get points for that.

(Scene shifts to the kitchen)
Grandpa Reg: Uh, where was I? Oh, yes! Now, the boys had a real monster on their hands, and they had to get him ready for the big night.

(At Phineastein's castle)
(Platypus monster chatters)
Phineastein: Come on! That-a-boy! Check it out, Ferbgor. (Throws a fish in the Platypus monster's mouth) To make sure we win that monster contest, I taught him a few tricks. Watch this. Play dead! (The platypus monster doesn't move) Huh? Huh?
Constance: (Still using the quill) So I said, "Oh no, you di-in't!" (Growling) And she said-- What was that? (Opens the door) What's going on down there? (Goes down the stairs) I will go straight to the angry mob and tell on you. (Opens another door) Aha!
Dr. Phineastein: Oh, hi, Constance. (Holds up the Best Monster Contest poster) We're gonna enter the Best Monster Contest.
Constance: How are you gonna answer a monster contest? (The platypus monster walks behind Constance) You don't even have a monster!
Platypus monster: (Growls)
Constance: He's right behind me, isn't he?
Dr. Phineastein: Yeah!
Constance: (Screams) (Steps back and grabs Dr. Phineastein's shirt) I'm. Telling. Mob. (Runs off, screaming. She comes out of the castle on a bike) Angry mob, come quick! (Stops the bike) Phineastein and Ferbgor have created a giant green monster!
Man 2: Didn't you tell us last week that they created a 2-headed cow?
Constance: We're wasting time! (Bikes off) Now let's hurry before the monster gets away!

Jekyll Doofenshmirtz: (Back to normal) Jameson, I think I found the problem. I had the Brew-Inator set to "Fairy Princess" by mistake. (Turns the dial) You know, in hindsight, I question even including a (Turns on the Concoction Brew-Inator) "Fairy Princess" setting to begin with. (The Concoction Brew-Inator whirs then turns off. He grabs the cup) But, you know, live and learn. Cheers! (Drinks the potion) Hmm... Evil has an interesting flavor. I must tell my friend, Dr.-- (He grunts and screams as he turns into a monster)
Jameson: Hmm... It actual worked.
Jekyll Doofenshmirtz: I know! I'm just as surprised as you are! Put her there, Jameson! Psych! (Laughs) (Jumps a few times) At last! A whole new world of evil has opened up to me! You know what this calls for, don't you?
Jameson: A rampage, sir?
Jekyll Doofenshmirtz: Exactly! Oh, and clean your uniform. (Laughs) Evil!
(Song: "He's Eviler")
He's public enemy number one
He's an evil, evil man
Jekyll Doofenshmirtz: That's me!

He's got a diabolical sense of fun
And an evil, evil plan
Jekyll Doofenshmirtz: Well, not a plan so much.

Oh, yes, He's eviler
Jekyll Doofenshmirtz: (While doing rabbit ears on two people having their picture taken) I'm winging it, actually.
More evil than he was before
Jekyll Doofenshmirtz: That's right.

Yes, He's eviler
Jekyll Doofenshmirtz: I don't think that's word.
And he's taking it door to door
Jekyll Doofenshmirtz: Oops, gotta go. (Chuckles) (Runs to Castle Phineastein) Evil! (Knocks the handle) (Evil laughing) Hyah! Got your nose! (Laughs) I got your... I... I... I really do have his nose. (The platypus monster is seen without his bill) Oops. Heh. Okay, okay. Well, we'll just put this back. (The platypus monster is seen with his bill, but slanted) There you go. Good as new.
Platypus monster: (Growls)
Jekyll Doofenshmirtz: EVIL!!!!
(The platypus monster roars and breaks the doors. It runs after Jekyll Doofenshmirtz)
Phineastein: Oh great! (Puts on his hat and jacket) We really have to stop losing our monsters.

(Woman screaming)
Villager: Blimey! Look what's coming!
Villagers: (Screaming) Run!
Villager 2: (Walks to his balcony, seen wearing only his underwear) I'm finally cured of my irrational fear that a giant platypus will see me in my underpants. (The platypus monster walks by) It's even worse than I imagined!

(The platypus monster walks down the cemetery. The camera pans to an Isabella Lookalike, who puts a flower in the pond. The platypus monster walks up behind her and growls)
Isabella lookalike: Whatcha doin'?

(Outside a cave)
Dr. Phineastein: Hello? (Bats squeaking) (Camera pans to the inside of the cave, showing three monsters) Are there any monsters in there?
Monster: Shh.
Dr. Phineastein: No, I guess not.

(At Dr. Phineastein's lab)
Constance: It was right here! You have to believe me! A giant platypus! (Mob grumbling) Wait! Mob, look! (Picks up a poster) The Monster's Ball! (Turns the poster) This is where they must have gone. (They walks out of the castle) Follow me!

Isabella Lookalike: La la la la Whatcha doin'?
Dr. Phineastein: We're looking for a giant platypus monster. Have you seen one by any chance?
Isabella Lookalike: Funny you should ask. We spent the entire afternoon together. We went swimming, had a little lunch. Did you know he eats raw snails? Ew! I stuck to PB and J on whole wheat.
Dr. Phineastein: Where is he now?
Isabella Lookalike: He went into town to enter the Best Monster Contest.
Dr. Phineastein: (Grabs Ferbgor and shakes him) Of course that's where he went! What were we thinking? Come on! (They run off)
Isabella Lookalike: Goodbye then! Tell him to save me a dance!

(At the Best Monster Contest, the building doors open. Waltz music plays in the background. Contestants walk into the building, and so does the platypus monster)
Dr. Phineastein: Thinks for the lift, mister! (He and Ferbgor hop off) Let's go!

(Inside the building, distinct chattering is heard as the platypus monster walks by)
Jekyll Doofenshmirtz: (Back to normal) Best monster, indeed. Wait till they get a load of pure evil! (Knocks off the punch bowl, cups and drink dispenser and puts the Concoction Brew-Inator on the table) We'll just adjust the dial, and-- (Turns around and notices the platypus monster. He gasps) Yah!
(The platypus monster chatters, and his bill slants. He grabs Jekyll, shakes him and punches him)
Contestant: Monster fight! (Starts a fight with a contestant dressed like a hippo. Soon everyone else starts fighting)
Jekyll Doofenshmirtz: (While being slammed on the floor) Really, really, I don't have your nose! Wait wait. Time out. Allow me one little drink before we continue. I'm parched, okay?

Dr. Phineastein: Here, boy! (At Ferbgor) I hope he hasn't gotten into any trouble.

Jekyll Doofenshmirtz: (Drinks a potion) (Chuckles) Just wait till my potion kicks in, you big, dumb monst-- (Grunts and turns into a fairy) What? But I-- I thought I had it set to-- (Flies to the Concoction Brew-Inator and turns the dial. The platypus monster grabs him and yelps. 2nd Flashback ends)
Doofenshmirtz: And, well, I forgot exactly what happens after that. (The lights come back on) Oh, hey, the lights! What do you know? (Gets up and stretches.. Perry also gets up and stretches) Oh, I got no time for my diabolical plan now. I've got the chiropractor at 4:00. (Walks Perry to the door) Could we pick it up tomorrow at, say, my evil scheme monologue? Good! (Camera zooms into him) But, you know, I wonder who actually did win the Best Monster Contest.

(Back in flashback)
Dr. Phineastein: Oh, there you are, platypus monster. (Camera pans to inside the building) And to think I worried you might get into some mischief.
(The platypus monster hacks up Jekyll Doofenshmirtz's wand)
Host: Ladies and gentlemen, we're ready to announce the winner of the Best Monster Contest.
Dr. Phineastein: Hey, we're just in time.

(Outside, Constance opens the building door. She looks around and smiles)
Constance: (Comes out of the building) Mob! It's here! The monster's in here!
Man: We're coming! Don't get your knickers in a twist.
Constance: (Walks into the building by the Concoction Brew-Inator) They are so busted! (Notices the Concoction Brew-Inator) Oh, refreshments! (Grabs the cup) This monster hunting is thirsty work. (Drinks a potion) That's a peculiar taste.
Jeremiah: Hey, Constance.
Constance: Oh, Jeremiah!
Jeremiah: I can't remember a day when you looked more beautiful. (Constance turns into a monster) Well, now I can.
Host: Ladies and Gentlemen, the winner of the Best Monster Contest is... (Camera pans to Constance as a spotlight shines on her) That!
(Two people of the Best Monster Contest give her flowers, and the other puts a crown on her)
Dr. Phineastein: Way to go, Constance! (Thumbs up) Good show!
Man: There it is!
Constance: Wait! No, no, no! I'm not the monster! (She screams, throws the flowers, and then runs through the wall. The mob chases after her)
Dr. Phineastein: Oh well. (Touches the platypus monster's hand) Win some, lose some, boy. (Camera zooms into him) You'll always be the biggest, baddest monster to us.
(The platypus monster smiles)
Isabella Lookalike: (Dressed in her contest outfit) I see you found your giant platypus.
Dr. Phineastein: That's right. And we'll never lose him again.
(Flashback ends)
Grandpa Reg: And that is why there are pumpkins.
Phineas: Um, Grandpa, you were telling us about a giant platypus monster.
Grandpa Reg: Ooh, that sounds exciting! Tell me about that.
Phineas: But you were-- I mean-- I didn't-- (Sighs) (The lights come back on) I've got nothing. Ferb?
Ferb: Platypus monsters are the only monsters to lay eggs.