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Derek is an antagonist in Milo Murphy's Law who is the son of King Pistachion and serves as the main antagonist of the episodes "Fungus Among Us" and "The Phineas and Ferb Effect".


In Missing Milo, he found a way on top of the Time Limo inside the Time Stream as Milo, Cavendish, and Dakota escaped from King Pistachion. When Dakota discovered Derek on top of their vehicle, he knocked him of the limo with a big sack of clocks.

In Fungus Among Us, Cavendish, Dakota, and Milo met Derek in 1965 after Milo got a call from Dakota (in the present). They wondered how he remained after Diogee peed on his father's seedling. So Derek explained his backstory and his own plan for overthrowing the human race. Back in the present, his plan seems to be working.

In The Phineas and Ferb Effect, he monologues in front of Melissa, Baljeet, Zack, and Buford about how he tried to run the Doctor Zone franchise himself back in 1965, but failed. When the kids run away from him he orders his army of Pistachions to chase after them. His army fails at first, but eventually they catch up with them and take Milo, Phineas, Ferb, Melissa, Zack, Baljeet, and Buford. However right when Derek is about to turn the kids into plants, Cavendish, Doof, Dakota, Orton, and Perry return from there adventure and cause a fight between Dakota's other versions of himself and the Pistachion army.

Throughout the confusion of the battle Milo, Phineas, Ferb, Cavendish, Dakota, Orton, Perry, and Doof make it up to a high point and call upon Professor Time, Doof's future self. Professor Time calls Orton to come with him to 1955 to destroy Derek before he started to hatch his master plan. Orton and Professor Time complete their goal and Derek and his monster Pistachion army fade away and die.


Like King Pistachion and the other Pistachions, Derek is bent on world domination. He spent seven years alone brainstorming his overthrow of the humans before carrying out a plan that would take fifty years to complete. The plan he created relied strongly on patience and stealth.

In spite of his dedication to carrying out his father's plans, Derek took a summer off to do some modeling. He calls himself young and foolish for doing so but claims he has no regrets. Derek became so focused on monologuing his evil scheme that he failed to notice his prisoners escape, much to his frustration. Afterward, he simply resorted to full out attacking them, attempting to destroy their time vehicle.

Physical Appearance

Like the other Pistachions, Derek is a large humanoid pistachio plant.

Disguised as an intern, he looked like a light skinned human with short brown hair and black, thick-framed glasses. He wore a white collared short-sleeved shirt with a blue-grey tie and a pair of pants with visible seams and a black belt. His shoes were brown loafers with darker laces and white socks.

Afterward, he donned a disguise to look identical to Orton Mahlson wearing his Doctor Zone outfit but soon removed the mask, keeping the costume. After removing the gift box, his right hand was exposed as plantlike, while his left hand remained human-like.

External Links

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Milo Murphy's Law
Milo MurphyZack UnderwoodMelissa ChaseDiogeeBradley NicholsonDoctor ZoneTime ApeSara MurphyMartin and Brigette MurphyAmanda LopezBalthazar CavendishVinnie DakotaHeinz DoofenshmirtzPerry the PlatypusElliot DeckerMrs. MurawskiKing PistashionMajor Francis MonogramCarl KarlVictor VerliezerRecurring RaccoonDerekJackieNormLove HändelVanessa DoofenshmirtzMort Schaeffer

Guest Characters: Phineas FlynnFerb FletcherCandace FlynnBaljeet TjinderBuford Van StommIsabella Garcia-ShapiroLinda Flynn-FletcherLawrence FletcherIrving Du BoisGiant Floating Baby Head

Season One: "Going the Extra Milo/Sunny Side Up" • "Rooting for the Enemy/The Undergrounders" • "The Doctor Zone Files/The Note" • "Party of Peril/Smooth Opera-tor" • "Worked Day/The Wilder West" • "Family Vacation/Murphy's Lard" • "Secrets and Pies/Athledecamathalon" • "The Substitute/Time Out" • "We're Going to the Zoo/School Dance" • "Battle of the Bands/The Math Book" • "The Little Engine That Couldn't/The Llama Incident" • "Missing Milo" • "Star Struck/Disaster of My Dreams" • "A Clockwork Origin/Perchance to Sleepwalk" • "Some Like it Yacht/Backward to School Night" • "World Without Milo/The Race" • "Love Toboggan/The Island of Lost Dakotas" • "Fungus Among Us" • "Milo Murphy's Halloween Scream-A-Torium" • "A Christmas Peril"
Season Two: "The Phineas and Ferb Effect" • "Snow Way Out/Teacher Feature" • "Picture Day/Agee lentee Diogee" • "Game Night/Pace Makes Waste" • "Cake 'Splosion!/Lady Krillers" • "Doof's Day Out/Disco Do-Over" • "The Ticking Clock/Managing Murphy's Law" • "Milo's Shadow/Sick Day" • "Field of Screams/Spy Little Sister!" • "Freefall/Milo's World" • "Dog Walker, Runner, Screamer/Now I Am a Murphy" • "Abducting Murphy's Law" • "The Goulash Legacy/The Dog Who Knew Too Much" • "Adventure Buddies/Ride Along Little Doggie!" • "Look at this Ship/Cast Party" • "Safety First/Cavendish" • "First Impressions/The Speech and Debate League of Death and Destruction Cross Town Explosion Event" • "The Mid-Afternoon Snack Club/Parks and Wreck" • "Escape/Milo in Space" • "Sphere and Loathing in Outer Space"
It's My World (And We're All Living in It)Don't Break MeRooting for the EnemyThe Doctor Zone Files Theme SongI've Got No ExcusesMister GoThe Show Must Go OnMurphy Family VacationLard WorldChop Away at My HeartWe're Going to the ZooI Need A Little TLCJust Roll With ItA Bumpy Ride TonightLlama LlamaI Can't Find YouSafety CzarI'm Taking A StrollWorld Without MiloToboggan of LoveI'm All Tied Up
DanvilleJefferson County Middle SchoolLard WorldMr. Slushy Franchise