Ash's Charizard/History/Original Series/Johto

Charizard also accompanied Ash on his journey to the Johto region, although it became apparent that it was unfairly superior to most of Ash's early competition. This was shown especially in The Double Trouble Header, where 's was beaten by Charizard exhaling and  was defeated merely by bouncing of Charizard's stomach. A single Flamethrower beat and allowed Charizard to win in the sweep, despite the disapproval of Misty and Brock. Team Rocket later capitulated on Casey's frustration, calling Charizard an illegal choice by Ash.

Charizard was used to weaken and help Ash capture a in The Chikorita Rescue. Its massive size compared to her came into effect when Chikorita ran towards it and tried to attack, Charizard responding by placing its foot out and blowing a small puff of fire after being instructed by Ash to only weaken her. Charizard's puff of fire ended up on Chikorita's single leaf and caused her to run around for a short amount of time before using to attack Charizard. Charizard was recalled by Ash after it and Chikorita fell into a large canvas of rocks.

In Fighting Flyer with Fire, it participated in Ash's first Johto Gym battle against Falkner, where it battled Falkner's. Due to the latter's impressive, Charizard started at a disadvantage, with Pidgeot's reflecting its Flamethrower back onto it. It was then knocked back down by a combination of Wing Attack and. Falkner told Ash to surrender but Ash refused and Charizard gained the strength to fight back and fly above Quick Attack. Charizard then baited Pidgeot, spinning around in midair when Pidgeot flew behind it and hitting it with Fire Spin, before seizing it and hurling it into the ground with Seismic Toss. Pidgeot was knocked out and Ash won the Zephyr Badge.

In Charizard's Burning Ambitions, Misty criticized Ash for using Charizard too often against fresh young Trainers, making him unbeatable but in an unfair way. Ash then met, who taught Ash and Charizard how to fly together. After arriving in the Charicific Valley, Charizard was humiliated by Liza's insults and proudly tried to show off its power, but was shown to be smaller and weaker than the wild Charizard who lived there. Charizard continued to pick fights and kept getting itself defeated until Liza locked them out of the Valley, having Charla throw Charizard into the lake and telling it and Ash to stay away until they had trained and reflected. Team Rocket sympathized with Charizard and helped it to stay awake in the lake, as well as making a false attempt to break into the Valley, allowing Charizard to defeat them and win acclaim from Liza, Charla, and the wild Charizard. Facing an emotional battle, Ash told Charizard that he did not want a weakling on his team and he would be fine without it, forcing Charizard to stay at the Valley to train and become more powerful. He then ran away from the Valley, knowing that if he stopped, he would not be able to say goodbye. Pikachu wished Charizard well and followed Ash, leaving its teammate and friend behind.

In Spell of the Unown: Entei, when it witnessed a news broadcast discussing how Delia Ketchum had been abducted by a mysterious Pokémon during strange events at Greenfield, Charizard departed the valley to assist Ash, arriving just in time to save him and Pikachu from falling to their deaths. Charizard subsequently assisted Ash in confronting the Entei created by the Unown, but even its natural power was insufficient against Entei's sheer strength and its ability to manipulate the environment thanks to its ties to the Unown, with Entei nearly breaking Charizard's neck. However, once Molly accepted the need to acknowledge reality, Charizard worked with Pikachu and Entei to defeat the Unown and end the illusion before it returned to the Valley to resume its training.

Once it returned to the Charicific Valley, Charizard took the role of bodyguard for Charla, and the two seem to have a sort of romantic relationship with each other. Liza occasionally visits the Dragon's Valley in Blackthorn City with the two Charizard. One such visit was in Great Bowls of Fire!, which coincidentally occurred when Ash was there for his final Johto Gym battle. Charizard helped Ash, Clair, Pikachu and calm the wild  that was rampaging in the Dragon Holy Land.

In Better Eight Than Never, Charizard battled against Clair's Dragonair in Ash's rematch with Clair by causing the water in the Gym's pool to evaporate with its Flamethrower and Fire Spin, thus depriving Dragonair of her protection. It then caught Dragonair with Seismic Toss and used Fire Spin to create a flaming twister to wear down Dragonair's defenses before she hit the ground and was knocked out. Ash surprised Liza by sending it back for training, knowing that Charizard still had a lot to learn. Ash later used Charizard in the Silver Conference during his fight against Gary Oak in Can't Beat the Heat!, as Brock had made a late-night call to Liza requesting Charizard for the battle. Gary's Blastoise and cut Ash's team down to only Charizard, who had to fight three opponents single-handedly. It managed to match Scizor's speed and took advantage of its significant type advantage, defeating Scizor with a single Flamethrower. Despite Gary's Golem's weight preventing Charizard from using its Seismic Toss, Charizard overcame it with a powerful Dragon Rage. Charizard struggled against Blastoise, as it had supreme defensive capabilities and could keep Charizard at bay with Hydro Pump. Thinking outside the box, Ash told Charizard to superheat the field, which forced Blastoise to spend time cooling the molten rock. This created a huge steam cloud and allowed Charizard to seize Blastoise at close range. Blastoise could still use to dodge Dragon Rage, so Charizard hurled Blastoise into the ground with Seismic Toss, defeating it and leaving Ash as the winner.

Charizard was then used in Ash's fight against in Playing with Fire!, where it came out against Harrison's Blaziken. Charizard's aerial advantage was negated by Blaziken's powerful legs and ability to maneuver in midair. Each Pokémon hit hard blows on the other, and their Flamethrowers were shown to be equal in power. Blaziken even managed to get up after a devastating Seismic Toss, while Charizard took a to the neck and continued on. A fiery clash between Flamethrower and Dragon Rage knocked both Pokémon down, but only Blaziken could get up, eliminating Ash from the tournament. Charizard once again returned to Charicific Valley, and it was revealed that it had injured Blaziken so badly that Harrison had to rest it in the next round, contributing to his loss.