Hocus Pokémon (Japanese: ポケモンまほうでだいへんしん！？A Huge Transformation with Pokémon Magic!?) is the 241st episode of the Pokémon anime. It was first broadcast in Japan on March 21, 2002 and in the United States on April 5, 2003.
Brock rarely meets a girl whom he doesn't find bewitching, but on encountering a particular young woman, even Ash and Misty can't deny that there is something magical about her. This is all explained when the young trainer explains that she is a practitioner of Pokémon magic. Excited to see the completion of a spell that promises to allow humans to understand the feelings and thoughts of Pokémon, Ash and friends embark on a quest to gather the hodgepodge of Pokémon-related ingredients required for the spell. Can anyone spare any Gloom nectar? What about iron shavings sorted by a Magnemite?
Ash and his friends continue through the mountains when a Murkrow approaches them and starts squawking. Then, a girl comes running out from a clearing, exclaiming that she finally found a Pikachu. The girl introduces herself as Lily, a Pokémon magician. Lily explains that she has been searching far and wide for bizarre things from different Pokémon such as a Thunderbolt from Pikachu. Misty asks Lily to perform magic for her because she once dreamed about being a Pokémon magician when she was little. Lily flicks through her spellbook and asks Misty if she'd like a smoother complexion, and Misty says yes. So, Lily mixes everything together and says a magic chant which causes a lot of smoke to rise from the pot. To Misty's surprise, the spell summons a bunch of Spinarak which use String Shot to give her smoother skin.
Ash is particularly intrigued about a Pokemon mindreading spell. Lily admits that the final ingredient is always missing - Stun Spore from a Parasect. Murkrow returns to everyone and brings them over to a wild Parasect. Ash volunteers to retrieve the Stun Spore, so he challenges Parasect to a battle. At first, it tries spraying Ash with Sleep Powder, but luckily, Murkrow blows it away. Then Parasect finally uses Stun Spore and Lily obtains it with a vacuum. Just then, Team Rocket appears and uses a long mechanical arm to kidnap Pikachu. Lily notices Meowth and wants to get the dirt from its claws, so she sends Murkrow to get it. Instead, Murkrow makes a hole in their balloon, sending them blasting off again. Pikachu falls from their clutches and into Ash's arms. Team Rocket is later seen slumped precariously over a rock ledge on top of a tall cliff. Wobbuffet pops out of his Poké Ball and adds more weight, and the ledge starts to crack. Lily, Ash, and his friends catch up to Team Rocket. Lily rushes to collect the dirt from Meowth's claws. As soon as she steps off the ledge, it breaks, and Team Rocket goes crashing into the bushes below.
Later, Brock asks Lily what else she needs and she tells the crew that she needs the tears of an Aipom. Ash is keen to see Lily’s magic, so he begins calling out for an Aipom. Misty and Brock doubt Ash’s approach will ever work, but to their surprise, an Aipom emerges from a nearby shrub. Lily is thrilled, but her enthusiasm sends Aipom fleeing. Meanwhile, the Rocket trio pop out of the nearby bushes. They heard about the spell, so they set out to capture the Aipom, Lily's bag and book so they can make a lot of money. When Aipom lets its guard down, Lily and the others charge at it. A net grabs Aipom, causing everyone to collide instead. Team Rocket strikes again in their balloon and Meowth uses the long arm to snatch Lily's bag. Then they recite their motto. Lily orders Murkrow to get her bag back, but Meowth uses the arm to punch Murkrow out of the sky. Jessie and James then make their getaway. Lily crumbles into tears, but Ash reassures her that they will retrieve her bag.
Team Rocket lands their balloon. Meowth scours through Lily's bag and grumbles that it's nothing but junk. Jessie and James inspect the spellbook, but the ancient language leaves Jessie confused. But James understands part of it. Jessie gets fed up, and so, to get Aipom to cry, she gets ready to punch it, but James stops her. She asks him what his problem is. He tells her to look at the ancient book. Jessie retorts that she could read tea leaves more easily than reading the book. James goes on to inform her that tears achieved through violence won't work. As a result, Team Rocket tries to figure out what they can do to make Aipom cry. James starts off by telling a bunch of corny jokes, but instead it makes Aipom yawn. Then Meowth performs a puppet show about a boy and his mother reuniting. It makes Meowth and James cry, but Aipom is still bored out of its mind. Jessie tells them they'll never jerk any tears from Aipom using clichéd storylines and overblown dramatics. She performs a princess as she waits for her beloved prince, though Jessie’s acting causes Aipom to drift off to sleep. Jessie gets angry and picks up Aipom to try and punch it, but once again James stops her.
Just then Ash and his friends catch up to Team Rocket and demand that the stolen stuff be returned. Jessie orders her Arbok into battle, but it is sent flying into the balloon's basket by Murkrow's Icy Wind. Then it's Ash's Pikachu against James's Weezing. Weezing uses Sludge, but the attack eventually runs out while trying to counter Pikachu's Thunderbolt. Meanwhile, Brock manages to untie Aipom who promptly runs off. Lily has Murkrow use Swift, which causes Weezing to ram Team Rocket into the basket. Pikachu performs Thunder on the balloon which makes it blow up and sends Team Rocket blasting off. Aipom finds this funny, laughing so hard that it produces tears of mirth. Ash quickly grabs a jar and tries to catch a tear, but he trips and takes a nosedive. Pikachu quickly grabs the jar and catches the tear instead. Both Lily and Ash thank Pikachu.
Lily mixes in all the ingredients for the spell and then she asks who will volunteer. Ash begs to be picked, so Lily selects him. Following orders, Ash finishes the spell with Pikachu's Thunderbolt. A lot of yellow smoke surrounds Ash and he comments that he felt a little like he's getting into Pikachu's mind. Then Lily, Misty and Brock gasp. Ash asks what happened. He looks up to his friends and queries how they got so big. Misty pulls out her mirror and shows Ash his reflection to reveal that he has been turned into a Pikachu. As Ash panics, Lily also reveals that the effect was unexpected. She glances through her book but finds that the next pages are too smudged to read. Misty asks Lily if Ash will be a Pikachu permanently, but she says of course not, just until the spell wears off. Ash calms down and decides to make the best of the weird situation. Misty and Brock are a little at ease as they watch Ash play around with Pikachu, Murkrow, and Togepi.
In the Japanese version, there was a picture of Jynx in Lily's book. The dub replaced it with a flower being kissed by a Jynx.
After Misty is attacked by the Spinarak, there was a short scene cut in the English dub. In this scene, everybody feels sorry for her because she has arachnophobia. The frequently used "clock" transition and part of the first shot of the next scene, a pan down to the main characters, are both cut from the dub.