Challenge of the Samurai (Japanese: サムライしょうねんのちょうせん！Challenge of the Samurai Boy!) is the fourth episode of the Pokémon anime. It first aired in Japan on April 22, 1997 and in United States on September 11, 1998.
Misty and Ash continue to wander the Viridian Forest when they spot a Weedle. As Ash battles it, he's distracted by a boy dressed as a samurai and calling himself (naturally) Samurai. Samurai challenges Ash to a battle, and Ash gets the advantage when his Metapod defends itself against Samurai's Pinsir. Samurai sends out his own Metapod—and a standoff begins.
A swarm of Beedrill interrupts the battle. Ash flees, but leaves his Metapod behind. The Beedrill grab Metapod and take it back to their hive. As Ash sneaks toward the hive to save Metapod, Jessie, James, and Meowth shows up to cause trouble. Ash is able to duck the angry Beedrill, and they instead focus their wrath on Team Rocket.
Metapod is mad at Ash for being abandoned. Has Ash learned his lesson about leaving his friends behind? Will Metapod evolve again? And will Samurai and Ash ever resume their battle?
As Ash, Misty, and Pikachu continue their way through Viridian Forest, Misty lets out a shrill scream. Ash turns to find her in a tree because she saw a Bug-type Pokémon, though he makes light of her fear. Then, he spots the Pokémon in question, a Weedle, and decides to catch it. He is forced to send out his Pidgeotto because Pikachu is asleep. Misty walks off, only to encounter a stranger named Samurai and his sharp sword. When he asks if she is from Pallet Town, Misty realizes the stranger is after Ash.
Meanwhile, Pidgeotto swoops and defeats Weedle, but, just as Ash is about to toss a Poké Ball, Samurai arrives and asks him if he is from Pallet Town. When Ash affirms it, Samurai challenges Ash to a Pokémon battle. The wild Weedle escapes and Ash reprimands Samurai for causing him to lose the Weedle. However, Samurai says that Ash allowed it to escape. The two then begin their Pokémon battle.
Ash uses his exhausted Pidgeotto against Samurai's Pinsir. Pidgeotto uses Sand Attack, but it is defeated by Pinsir's Tackle. Ash then sends out his Metapod, which wins after its Harden breaks Pinsir's pincers. Samurai sends out his own Metapod and the two Metapod continue to use Harden in a battle of willpower, leaving Misty and Pikachu wondering if the match will ever end. After spotting a Beedrill swarm, Samurai recalls his Pokémon and flees, though Ash checks his Pokédex for details. A Beedrill kidnaps Ash's Metapod, despite Ash's attempts to return his Pokémon. Pikachu shocks a Beedrill and Misty grabs Ash to start running, catching up with Samurai. They hide amongst some shrubs, only to encounter a hive of Kakuna. When the Kakuna evolve into more Beedrill, the group flees to Samurai's log cabin.
Samurai rebukes Ash for putting his Metapod in danger, then admits that he lost against three other Trainers from Pallet Town, including Gary. However, he insists that Ash is a novice. Ash keeps quiet, and promises himself that he will find Metapod the next day and look after him better from then on. During the night, he is unable to sleep and can only think about his Metapod.
Early the next morning, Ash begins his search for Metapod. He sees him lying at the base of a tree, surrounded by many Kakuna, and attempts to sneak forward through the grass towards him without alerting the Beedrill swarm. However, he is interrupted by Meowth, who jumps on the back of his head. A moment later, Jessie and James appear on a cliff overhead, and launch loudly into their motto, ignoring Ash's warnings that they will alert the Beedrill. The sound awakens the Beedrill, who prepare to dive-bomb Ash and Team Rocket. Ash rolls underneath their attacks and reaches Metapod. Jessie and James attempt to take cover in their cardboard van, but some Weedle have begun to chew through it, and they run instead.
Ash attempts to recall Metapod to his Poké Ball, but he shakes in disagreement. With a Beedrill fast approaching, Ash runs with Metapod in his arms. Seeing a look of sorrow in Metapod's eyes, Ash realizes that he has lost Metapod's trust. Ash attempts to explain what happened, saying that losing Metapod was all Samurai's fault. However, Ash suddenly realizes that he is lying to himself and to Metapod, and admits that losing Metapod was his fault and his alone. Ash is upset upon realizing that it was his carelessness that put his Pokémon's life in danger, and, amid tearful apologies to Metapod, he sincerely promises to stop making excuses and take better care of his Pokémon. As Samurai, Misty, and Pikachu arrive in a protective bug net, Metapod leaps into the path of a Beedrill's Twineedle, sparing Ash. Ash cradles Metapod, thinking he has been badly injured, but he instead begins to glow. The hole in his shell has triggered Metapod's evolution into Butterfree. Ash gazes happily at his first fully-evolved Pokémon, and even Misty isn't fearful, going so far as to call Ash's Butterfree beautiful.
Another swarm of Beedrill appear, but this time, Ash orders his Butterfree to use Sleep Powder, which puts the bee-like Pokémon, and also Team Rocket, to sleep and allows the group to escape. Samurai applauds Ash for his control over Butterfree so soon after its evolution. He then shows Ash and Misty the path out of Viridian Forest to Pewter City. He also tells Ash that he takes back his criticism and refers to himself as a novice. Ash, Pikachu and Misty continue towards Pewter City to earn Ash's first GymBadge. Team Rocket, meanwhile, is left wrapped up like Kakuna amongst a hive of angry Beedrill.
This is the first episode not to have the word "Pokémon" in its title.
This is the first time the lines "Prepare for trouble! / And make it double!" are included in Team Rocket's motto.
In this episode, Metapod and Kakuna's evolution processes are depicted as their shells cracking and their evolved forms emerging, leaving behind an empty carapace, similar to real-life insects' emergence from pupation. Inlaterepisodes, however, Metapod and Kakuna are shown to evolve like any other Pokémon.
During the Metapod vs. Metapod battle, each side uses Harden in a futile attempt to defeat the other. However, Ash's Metapod should technically know Tackle as well, since it evolved from a Caterpie. It does, in fact, appear to use this move later to protect Ash from a Beedrill's Twineedle attack.
When Ash, Misty and Samurai are settled down for the night and Ash is shown to be awake and worrying about Metapod, "Satoshi", Ash's Japanese name, is seen to be written on his sleeping bag.
Samurai blames Ash for letting the Weedle escape, even though he only failed to catch it due to Samurai himself interrupting his capture attempt.
This episode was banned in South Korea due to a cultural problem.
In the Dutch and Polish dub of the episode, Ash refers to Gary as "Bailey" while talking with Samurai. The same error appears in Pokémon Stickers series 1 by Artbox, possibly indicating a preliminary name for Gary in the anime's dubbing production.
Many times in this episode, when referring to multiple of a Pokémon, characters add "s" on the end of the name when the plural of a Pokémon is the same as the singular.
During the recap when Caterpie evolves, Ash's eyes are red in color.
When Samurai first points his sword at Ash, Ash's gloves disappear.
After Samurai challenges Ash to a match, Pikachu says "Pika?" and his mouth is white instead of the usual pink.
Right before Ash and Samurai battle, Pikachu says his name but his mouth doesn't move.
The hole a Beedrill makes in the door of the cabin disappears in the next shot.
When Ash sets out the next morning to look for Metapod, Meowth kicks Ash in the head and scratches him. After he starts crying, Jessie and James are shown on top of the cliff above him. Ash runs off after they finish reciting their motto, during which time Meowth is still next to him. However, when the camera cuts to Jessie and James jumping off the cliff and running after him, Meowth is shown jumping off with them.
At the end of the episode, Samurai's sword appears smaller than normal.
Also at the end, in one shot Samurai is standing under trees, but the trees disappear in his close-up.
When Misty screams "Bug!", Ash gets in a cow costume and suggests that the bug is a "cowterpie". In the Japanese version, he instead makes an untranslatable pun: Misty says "Mushi! Mushi! Mushi! ...Mushi!" which means "Bug! Bug! Bug! ...Bug!". Ash then says "Ushi?", meaning "Cow?".
The word "Mika" on Jessie's Kakuna disguise is painted out in the dub.
The narrator talking at the beginning of the episode after the recap was removed in the dub.
Misty's bikini scene was removed from the Hindi dub.