The Monster of Phineas-n-Ferbenstein

“The Monster of Phineas-n-Ferbenstein” is the first half of the 22nd episode of the first season of the television series Phineas and Ferb. It originally aired on Disney Channel in the United States on October 17, 2008. It was story by Jon Colton Barry and Martin Olson, and directed by Zac Moncrief.

A rainy day causes 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, creating a platypus monster. While locked in his own building, Doofenshmirtz tells Agent P the story about his ancestor, Jekyll Doofenshmirtz, who made a concoction brewed to turn him into a monster.

Plot summary
On a stage, Phineas (Vincent Martella) and Ferb (Thomas Sangster) 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 (Dee Bradley Baker) is, and cut to him in his lair, Major Monogram (Jeff “Swampy” Marsh) 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 because of water damage, and then worries about the time, rushing to go to his cousin’s wedding after telling Perry to stop Doofenshmirtz.

Back at the Flynn-Fletcher house, Grandpa Reg (Malcolm McDowell) 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 knows what they’re going to do today. Heading back to the castle, Candace (Ashley Tisdale) 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 their disproving castle governess, who is writing with her quill. She then yells at them to keep it down, and then the boys hide after bringing a giant Platypus monster to life. 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 the time, he tells Perry the story of his ancestor, Jekyll Doofenshmirtz (Dan Povenmire). 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 (Greg Ellis), 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 that she’s telling Mob. She bicycles down to the Mob, and tells them that the boys have made a monster.

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 Isabella lookalike (Alyson Stoner), while Constance tries to get the Mob to go to Monster Contest where she’s sure the boys are. 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 escapes from the monster, or 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. The winner is Constance, who has just turned into a Hyde-like monster after accidentally drinking the brew. Phineastein tells the Isabella lookalike that they’re never going to lose the monster again, and Reginald ends the story 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. He responds with, “Platypus monsters are the only monsters to lay eggs.”