Without a doubt, Ash's closest companion during his journey was Brock. Brock appears in over 500 episodes of Pokémon anime, a feat shared only by Ash, Pikachu, and Team Rocket. While Brock hasn't always received his fair share of the spotlight, he's still had plenty of opportunities throughout this time to stand out and showcase his skills.
Brock often played a supporting role in Ash's traveling party, putting his older brother's skills to use while ensuring that Ash and his friends remained well-fed and on the right path. Brock was often crucial in keeping the group on track and provided valuable advice based on his experience as a Gym Leader and Pokémon Breeder, and eventually as a Pokémon Doctor. Brock has also achieved some significant achievements throughout the series that are worth recognizing.
10
Leave that to Brocko!
Pokémon Diamond and Pearl, episode 14
A lost Nuzleaf is wreaking havoc as it is terrified of humans. Brock arrives and uses his knowledge of Pokémon to help calm him, approaching carefully and using tactics such as whistling a specific song to ease Nuzleaf's fears. Brock manages to gain Nuzleaf's trust with the help of his Bonsly, but they are soon attacked by Team Rocket and captured. Brock's Bonsly evolves to help them escape, and Brock is able to defeat Team Rocket alone. Nuzleaf returns home and everyone goes on their way.
This episode shows how good Brock can be with Pokémon, even wild Pokémon who are wary of humans. It's perhaps one of the first signs of Brock's shift in focus from breeder to doctor, as Brock can't help but want to help the lost Pokémon. It's also one of the few times that Brock's Pokémon evolves on screen, making it an exceptionally noteworthy episode.
9
Just waiting for a friend
Pokémon, the original series, episode 232
While exploring the mountains, Ash, Brock and Misty stumble upon an old mansion inhabited by a strange woman, with whom Brock immediately falls in love. Calling herself Lokoko, she is surprisingly receptive to Brock's advances and even agrees to marry him. However, Ash and Misty begin to notice signs that something is not right in the mansion and try to warn Brock. They discover that the original owner of the mansion looks like Brock, but has been gone for 200 years. Lokoko is revealed to be an illusion created by the man's Ninetales, who has been waiting for him all this time. Ninetales' old Poké Ball is destroyed, allowing her to be free.
This episode plays a bit with Brock's girl-crazy reputation, continuing his streak of bad luck with women by making it an illusion. It is popular among fans, as Ninetales is an interesting character and a rare example of a Pokémon that outlived its master. Brock proves he's in it for more than just love, helping Ninetales even after the deception is revealed–after all, he still cares a lot about Pokémon.
8
Showdown in Pewter City
Pokémon, the original series, episode 5
Brock's debut episode finds him fulfilling his role as Pewter City's gym leader. Ash challenges Brock, but is almost immediately forced to give up due to Brock's Onix's great power and size. While Ash is disappointed, a strange man shows him what Brock's life is like, taking care of nine younger brothers alone. Ash supercharges Pikachu for their rematch and impresses Brock with his increased power. Ash wins the battle thanks to some innovative thinking, and the strange man reappears, revealing himself to be Brock's father. Brock's father encourages Brock to travel with Ash and stays to take care of his brothers.
BRock gets a strong introduction here, showing him to be a responsible guy as well as a skilled gym leader.. Brock's home life situation is a bit exaggerated, but it goes to show that Brock has experience caring for others, a role he quickly takes on for his fellow travelers as well.
7
Love, Totodile Style
Pokémon, the original series, episode 153
Ash's Totodile falls in love with an Azumarill they meet in a lake, but struggles to impress the demanding Water-type Pokémon. Azumarill's trainer appears and Brock soon falls in love with her as well. Brock agrees to help Totodile win Azumarill's heart and begins working with him to impress her. Azumarill is soon captured by Team Rocket, and then Totodile must save her. Despite successfully saving Azumarill, it soon becomes apparent that Azumarill has another love: Golduck. Brock comforts Totodile, saying that love is still worth fighting for.
Although Brock's love life is often the butt of jokes in the anime, Brock's advice in this episode is pretty solid. This proves that despite his girl-crazy attitude, Brock has a good understanding of what love really is and realizes when it's time to give up.
6
When regions collide
Pokémon Sun and Moon, Episode #43
Although Brock had been away for some time Sun and Moonhe reappeared (alongside Misty) in this episode. Here, it is revealed that Brock has mastered the use of Mega Evolution. Brock fights Ash's new friend Kiawe and absolutely dominates the battlefield with Steelix. Steelix Mega Evolves and then uses a Z-move from Kiawe's Turtonator and survives with ease. Brock manages to finish the battle and wins, proving that his skills only improved in Ash's absence.
It's always good to see old characters like Brock and Misty returning, so the episode is noteworthy for that alone. Brock's mastery of Mega Evolution shows he hasn't given up on his battle skillseven with his new goal of becoming a Pokémon Doctor.
5
Poké Ball Danger
Pokémon, the original series, episode 83
After arriving in the Orange Islands with Ash and Misty, Brock soon falls in love with the local teacher, Professor Ivy. He demonstrates his ability to care for Pokémon by preparing a special meal for a non-eating Butterfree, and soon takes on menial tasks in the laboratory, cleaning and cooking. Brock is impressed when Professor Ivy risks herself to save an injured Pokémon and makes the decision to stay behind when Ash and Misty leave. The trio broke up for the first time since getting together.
Brock shows that he's not just mindlessly following Ash; Brock has his own goals and believes that staying there will help him with his goals. While his affection certainly plays a role, Brock makes this decision with a cool head, revealing his more responsible side. Unfortunately for Brock, some unknown incident occurs, which ends with Brock returning to Kanto and not wanting to talk about what happened.
4
A family that fights together stays together!
Pokémon Chronicles, Episode #5
A special episode focused exclusively on Brock, sees Brock returning to Pewter City after his adventures in Johto with Ash, only to discover that his mother is back and has turned the gym into a Water-type gym. Brock tries to get his father to fight back (literally, in a Pokémon battle), but to no avail. Brock's brother Forrest is especially upset, as he was acting as gym leader in Brock's absence. Brock himself defies his mother and easily defeats her, earning the right to return the gym to the Rock type.
Revealing Brock's mother, this episode goes a long way toward explaining why Brock is the way he is. With both parents constantly following their own whims, it's easy to see why Brock had to step up and become the responsible parent for his siblings.. Brock was forced to mature at a young age, and that fact shaped his character more than any other.
3
Pokemon Fashion Flash
Pokémon, the original series, episode 28
Brock asks the group to take a short detour so he can visit a legendary location among Pokémon breeders. There he meets Suzie, a creator who has won awards for three consecutive years. Suzie has been struggling since a new salon opened nearby – a salon secretly run by Team Rocket. Brock helps Suzie win back some of her clientele by introducing real Pokémon breeding techniques. Suzie decides to embark on her own journey and asks Brock to look after her Vulpix.
One of the first episodes to focus on Brock's goals, Suzie is a rare case of Brock behaving around a new girl, likely because he already had an established respect for her ability. Brock shows that his talent for preparing Pokémon food is truly remarkableand Suzie's trust in Brock's abilities is what leads her to give him her Vulpix, making the Pokémon a symbol of her intention to grow as a breeder.
2
Heart of Fire! Heart of Stone!
Pokémon Sun and Moon, Episode #103
Brock and Misty pay Ash a visit while he is in the Alola region. They go with Ash and his friends to Kiawe's family farm, where a baby Kangaskhan was injured. Brock puts his Pokémon Doctor knowledge to use, using a Comfey given to him by Nurse Joy to help calm his angry mother. Brock treats the injury and soon Kangaskhan is as good as new. Brock expresses interest in meeting Olivia, another Rock-type trainer, and when they meet, they engage in battle. The two quickly team up and even defeat Team Rocket with a double Z move.
A rare case of Brock's interest in a woman's return, Brock and Olivia make a cute pair, although the relationship isn't going anywhere as Brock must return to Kanto. Most noteworthy is Brock putting his medical training into practice, showing that he has really been learning a lotand has the bedside manner worthy of a doctor.
1
The Brockster is in fashion!
Pokémon Diamond and Pearl, Episode #190
The Sinnoh Pokémon League has ended and Ash, Brock, and Dawn are heading back to Twinleaf Town, realizing that this journey will soon end as well. Team Rocket, following behind, manages to disturb a group of Tentacruel, leading them to attack the ship and poison a trainer's baby Pokémon. Brock tries to help treat his injuries, but he needs special fruit. They search the ship from top to bottom, finding only a few items that can help. Brock's Happiny evolves into Chansey and is capable of using Soft Boiled, a move that heals Pokémon, helping the baby Pokémon recover without berries.
This is the episode where Brock considers his new goal to be a Pokémon Doctor, after taking care of the babies. It's near the end of his career as a main character, as training to be a Pokémon Doctor will require schooling, not travel. It's this decision that leads Brock to part ways with Ash, and shapes his character from this point forward, giving him some of the greatest character growth in the entire series. Therefore, this episode is undoubtedly one of the Brock's best episodes node Pokémon anime.