L.O.V.E.M.U.F.F.I.N.

L.O.V.E.M.U.F.F.I.N. (League Of Villainous Evildoers Maniacally United For Frightening Investments in Naughtiness) is an organization dedicated to promoting evil. It was presumably founded by Dr. Heinz Doofenshmirtz.

L.O.V.E.M.U.F.F.I.N. made its on-screen debut in "Nerdy Dancin'", when its name was established by Doofenshmirtz. In that episode, they had a meeting in which Norm made a large amount of potato salad for a pot luck picnic and press conference. When they realized that no press was present and they were at the Let's All Dance Until We're Sick filming in Danville, Doofenshmirtz resorted to redirecting them to the studios where the show was being held and take over the dance competition, seeing this as an opportunity to spread terror via television by announcing their existence. However, they failed on account of a combination of two things: their poor dancing skills and decisive intervention by Agent P, with the end result on their part was a disaster, as many of them - including Doofenshmirtz - were badly mauled and ended up in the hospital shortly thereafter, leading Doofenshmirtz to comment from his hospital bed that the show would be more apt if it was renamed Let's All Dance Until We're in Intensive Care.

As the second annual Inator Creator Competition was being held, a number of O.W.C.A. agents, including Perry, were sent in for reconnaissance but were all captured and incarcerated. Dr. Doofenshmirtz was hoping to win the prize belt himself. However, his inator wasn't complete and he struggled to finish it in time for the presentation. Intending to buy himself time, he activated a fog machine and hampered visibility in the convention, along with the whole of Danville. In the confusion, Rodney managed to activate his own invention, a Fog-Clear-Inator (which turned out to be an gigantic electric fan), which cleared up the room. Doofenshmirtz compensated for this by helping the O.W.C.A. agents escape and releasing them into the convention to destroy the competitors' inventions. At the end of the ensuing fight, the electric fan was the last invention standing. By that time, Doofenshmirtz rolled his crudely-built invention out onto the convention floor. After setting it by the electric fan, he activated it. A fist with a boxing glove sprung out of it, called by Doofenshmirtz the "Eradicate Rodney's Inator-Inator", promptly smashing the electric fan to pieces, completely destroying it in the process, and forced Rodney to run off crying.

Doofenshmirtz was declared the winner by default. Although Heinz was delighted to win, exclaiming that default was "My favorite way to win", he was dissapointed to find out that the trophy belt was destroyed in the fight. The judge instead handed him a red balloon to substitute for the original prize. Just as Heinz dubbed the prize, "Balloony II", a herd of robotic bulls it drew in stormed into the convention center and decimated the Quanity Inn building.

L.O.V.E.M.U.F.F.I.N. later televised a competition in the Danville Arena where the winner would become the supreme leader of the organization. Agent P was also at the event, having been brought there by Doofenshmirtz after being captured in a bottle. For the opening, the dancers, including Doofenshmirtz, sang the song Evil Tonight on stage. Lawrence Fletcher, who arrived at the arena due to misreading the location of his speech, entered through a trapdoor in the stage and is mistaken as one of the top three contestants. The other two contestants were Dr. Doofenshmirtz and Rodney; Dr. Dimunutive was also a finalist, but was disqualified during the production number due to his height. They compete in various competitions, such as the Mechanical Mother competition and the Swimsuit competition, all of which Lawrence unsurprisingly loses due to his politeness and also because he doesn't fully understand what the contest is for. Rodney attempted to use Doofenshmirtz's Make-Everything-Evil-inator, which he renames the Make-Everything-Evil-izer to make himself more evil and thus secure his win. Doofenshmirtz accuses him of stealing his idea and they both fight to be shot with the -inator first. The fight accidentally makes the -inator hit Lawrence, turning him evil and causing him to win the last round of the competition, where the contestants try to intimidate the others with their most evil glare. Lawrence wins by so many points that he is elected Supreme Leader of L.O.V.E.M.U.F.F.I.N. Major Monogram advises Perry, through Perry's wrist communicator, to remind Lawrence of who he really is to turn him back to normal. Perry uses his jet pack to escape and turn the dart that Phineas and Ferb are riding on towards the Danville Arena and land in the middle of the arena. Lawrence sees them and he goes back to normal. He tosses aside his Supreme Leader medal, thus resigning as leader. Lawrence, Phineas, and Ferb exit the arena, with Lawrence believing that he had just become the king of the pharmacists.