The beak 3 is a parody of Iron Man 3
Phineas recalls a New Years Eve party in 1999 where he meets scientist Ginger Hirano, the inventor of Extremis, an experimental regenerative treatment intended to allow recovery from crippling injuries. Disabled scientist Thor (Phineas an Ferb) offers them a place in his company Advanced Idea Mechanics, but Phineas rejects the offer, humiliating Killian. Years later, Phineas's experiences during the alien invasion of New York (The Avengers (paulodejesus18 version)) are giving him panic attacks. Restless, he has built several dozen Beak suits, creating friction with his girlfriend Isabella. Meanwhile, a string of bombings by a terrorist known only as the Khaka Peü Peü has left intelligence agencies bewildered by a lack of forensic evidence. Stark's security chief Irving Do Boid is badly injured in a Mandarin attack, causing Phineas to issue a televised threat to the Khaka Peü Peü, who responds by destroying Phineas's home with helicopter gunships. Ginger, who came to warn Phineas, survives the attack along with Isabella. Phineas escapes in an Beak suit, which his artificial intelligence Princess Luna. pilots to rural Tennessee, following a flight plan from Phineas's investigation into Khaka Peü Peü. Phineas's experimental armor lacks sufficient power to return to California, and the world believes him dead.
Teaming with Melissa, a precocious 7-year-old girl, Phineas investigates the remains of a local explosion bearing the hallmarks of a Khaka Peü Peü attack. He discovers the "bombings" were triggered by soldiers subjected to Extremis, which at this stage of development can cause certain subjects to explosively reject it. After veterans started exploding, these explosions were falsely attributed to a terrorist plot in order to cover up Extremis's flaws. Phineas witnesses Extremis firsthand when Khaka Peü Peü agents Gretchen (Phineas and Ferb) and Holly (Phineas and Ferb) attack him. With Melissa's help, Phinead traces the Khaka Peü Peü to Miami and infiltrates his headquarters using improvised weapons. Inside he discovers the Khaka Peü Peü is actually an English actor, who claims he is oblivious to the actions carried out in his image. Thor, who appropriated Ginger's Extremis research as a cure for his own disability and expanded the program to include injured war veterans, reveals he is the real Khaka Peü Peü, using the actor as a cover. After capturing Phineas, Thor shows him Isabella (whom he had kidnapped) being subjected to Extremis, in order to gain Phineas's aid to fix Extremis's flaws and thus save Isabella. Thor kills Ginger when she has a change of heart and tries to stop him.
Thor has manipulated American intelligence agencies regarding the Khaka Peü Peü's location, luring Ferb – the former War Machine, now re-branded as the Iron Patriot – into a trap to steal the armor. Phineas escapes and reunites with Ferb, discovering that Thor intends to attack the mayor of Danville, Roger Doofenshmirtz, aboard Air Force One. Phineas saves some surviving passengers and crew but cannot stop Thor from abducting Roger and destroying Air Force One. They trace Thor to an impounded damaged oil tanker where Thor intends to kill Roger on live television. The vice mayor will become a puppet leader, following Thor's orders in exchange for Extremis to cure his young daughter's disability. On the platform, Phineas goes to save Isabella, as Ferb saves the mayor. Phineas summons almost all of his Beak suits, controlled remotely by Luna, to provide air support. Ferb secures the mayor and takes him to safety, while Phineas discovers Isabella has survived the Extremis procedure. However, before he can save her, a rig collapses around them and she falls to her apparent death. Phineas confronts Thor and traps him in an Beak suit that self-destructs, but fails to kill him. Isabella, whose Extremis powers allowed her to survive her fall, intervenes and kills Thor. After the battle, Phineas orders Luna to remotely destroy each the Beak suit as a sign of his devotion to Isabella, while the vice president and the actor are arrested. With Phineas's help, Isabella' Extremis effects are stabilized, and Phineas undergoes surgery to remove the shrapnel embedded near his heart. He pitches his obsolete chest arc reactor into the sea, musing he will always be the Beak.
In a present day post-credits scene, Stark wakes up Dra. Fluttershy , who fell asleep listening to Phineas's story.
- Phineas - Tony Stark
- The Beak - Iron Man
- Isabella - Pepper Potts
- Ferb - James Rhodes
- Thor (Phineas and Ferb - Killian
- Ginger Hirano - Maya Hansen
- Holly (Phineas and Ferb) - Savin
- Gretchen (Phineas and Ferb) - Brandt
- Irving do Boid - Happy Hogan
- Princess Luna - J.A.R.V.I.S
- Roger Doofenshmirtz - President Ellis
- Fluttershy - Bruce Banner