Peter Piper, a photographer, visits a laboratory where a spider plant with teeth has been created. Piper attempts to take a picture, but is bitten on the bottom by a plant coming down from the ceiling.
Piper leaves ...展开the lab via a back door, sits in a dark alley, sweating, and begins to turn green. His molecular structure is shown to be changing with the text "This means something very nasty is happening". When he wakes up, he finds that when he stretches, plants shoot from his arms. He is also able to climb walls. Suddenly a sweeper, who is also crawling on the wall and cleaning the walls appears there.
Piper is then shown sitting on a roof, when he sees that Jane-Mary is getting mugged. He goes to save her, but he realizes that he needs a costume. He appears in the alley in an Indian costume, a fairy costume and eventually in his Spider-Plant suit. He saves Jane-Mary, who falls in love with him. He suggests to her that he might be Peter Piper, only to be told that Piper is a loser.
Spider-Plant Man is then shown landing in an alley where another man says he is his enemy. Peter guesses that he is The Green Goblin, Doctor Octopus, the Itchy Skull, or Not The Human Man, but it appears to be Batman. Batman tells him that no one cares about him anymore and that everyone only wants spiders nowadays. He no longer has the Batmobile, owning only a dilapidated "Bat-Clio". Even Robin has abandoned him. "Apparently he was only in it for the money." He tells Piper that he has kidnapped Jane-Mary and Piper guesses that she is on Tower Bridge.
Spider-Plant Man swings through London, wondering where Tower Bridge is, while Batman, who couldn't get his Bat-Clio to start, takes the Underground to Tower Bridge. Jane Mary is bound to a flag on Tower Bridge by Batman. Spider-Plant Man and Batman begin to fight, where they are mistaken by a reporter for Fathers 4 Justice activists. Peter fires a spider plant at him, followed by Batman throwing his boomerang and the battle goes on.
Batman's sidekick Robin (played by Tony Robinson) arrives, and makes a deal with Batman for 20% of the profits on Batman products and a Robinmobile and starts attacking Piper. Whilst hanging from Tower Bridge, Spider-Plant Man makes a deal with Robin for 25% on all pajama sales and his own cereal brand with real marshmallows, Robin switches sides and attacks Batman. Batman is punched off the tower and lands on the reporter. He hijacks a scooter and gets away.
Spider-Plant Man and Jane-Mary start to kiss. Robin tells Peter it's time to go and moments later Peter punches him. He then asks Jane-Mary whether she will marry him, and she responds, "Who's asking me, Spider-Plant Man or the man behind the spandex?" He replies, "You choose". Jane-Mary is then shown lying in the sun on a beach, next to Piper who is still in his Spider-Plant suit.