Pignite as a Tepig during his debut appearance, he was seen to be sad and desperate when his snout got tied and like Ash's Charmander and Chimchar, Tepig was abandoned by his trainer due to being weak in battle (in his case he was abandoned and left to starve). When Pikachu was captured by Team Rocket making Ash became desperate to save Pikachu, Tepig became serious and determined as he manage to break their protective barrier with a single Ember causing the group to escape by air via para glider. Tepig happily took a liking to Ash due to his caring nature to his Pokémon which is the reason that he allowed Ash to capture him and let him join the team.
Upon evolving into Pignite, he is a brave and confident Pokémon and also an adept battler similar to Ash's Infernape when he unleashes his Flame Charge to resemble Infernape's Flare Blitz and his newly learned Fire Pledge where he punches to the ground creating a deadly fire pillars in all opponents. He maintains his friendly relationship to other Ash's Pokémon especially Snivy who convinces him to battle his former Trainer while he was in his pre-evolved form.
He also gains a strong friendly bond with Ash's Charizard when Ash decides to let it rejoin in his team during his travels in Unova and the Decolore Islands. When Pignite have bullet shells stuck on his nostrils, Charizard does a giant swing at him, but spares him when he falls into the edge due to his fear of heights. When Charizard is knocked off the fight, Pignite becomes very fierce and determined to fight his enemies and later both are seen teaming up to unleash their Flamethrowers. Although, Pignite's Flamethrower is not as strong as Charizard's.
Before the events of The Battle Club and Tepig's Choice! in the Accumula Town Battle Club, Pignite was abandoned by his trainer as a Tepig. The then-yet to be identified trainer had tied a rope around Tepig's neck, tied it to a post, and left it to die. Ash discovered Tepig eating the bait he and Iris laid out for him and proceeded to catch him. After being fed some Pokémon food by Ash, who became desperate to save Pikachu from Team Rocket, Tepig became serious to fight them as it destroys their barrier using Ember to make them escape via para glider. Don George also recognizes Tepig as the one tied up in the post after being abandoned by his Trainer and he allows Ash to take care of him who invites him to join his team which Tepig happily accepts and gets caught.
Since Ash promised to use him in his first Gym Battle, Tepig fought against Chili's Pansear in Triple Leaders, Team Threats. His attacks did not do much damage to Pansear, whose Fire Punch, Flamethrower and Dig attacks hit Tepig hard. Tepig then managed to bite Pansear's tail and send it flying and manage to defeat it with both Ember and Tackle, winning Ash the first Gym battle round until Ash defeats Cilan and his Pansage by using Oshawott as his final Pokémon.
In A Rival Battle for Club Champ!, Tepig battled against Trip's Tranquill. Like Oshawott, Tepig was defeated by Tranquill's Super Luck-boosted Aerial Ace. Tepig battled Lenora's Lillipup in The Battle According to Lenora and was forced back into his Poké Ball by Lillipup's Roar, then fought against it again after Oshawott lost against her Watchog, but he lost after being hit by a powerful Take Down. After training in Rematch at the Nacrene Gym, he battled Lenora's Herdier and he won using his newly learned Flame Charge attack after it clashed with the opponent's Giga Impact.
In Gotta Catch a Roggenrola! Tepig is used to fight a wild Roggenrola after Oshawott had fainted during the fight and he too being defeated by it with both Sandstorm and Stone Edge combination. After being recovered at the Pokémon Center, Tepig is used again to release Roggenrola from Team Rocket's capture and later defeating Jessie's Woobat using Ember. He also manages to defeat both Woobat and James' Yamask using Ember and allowing Pikachu and all of the Roggenrola to destroy the machine using Electro Ball and Flash Cannon combination forcing the trio to flee using jetpacks.
After the incident, Tepig gains a rematch against the wild Roggenrola after he lost the first. Tepig eventually gains the upper hand despite its type disadvantage by hitting it with a Tackle followed by a Flame Charge and it allows Ash to capture it.
In Battle For The Underground!, while trying to remove Team Rocket from the Battle Subway in Nimbasa City, Tepig teams up with Iris' Axew and Ash's Roggenrola using a combine power of Dragon Rage, Ember and Flash Cannon combination to move the train faster. Upon using the full power to speed up the train as both unleashed their moves, Tepig tried to use Ember but instead learns Flamethrower in the process due to Ash's determination as the Subway Masters Emmet and Ingo congratulates Ash for letting his Tepig to learn a new move as Ingo sent his Chandelure to attack Team Rocket's ghost train with Will O Wisp but James detonates the train to escape while in smoke to make them get through their helicopter piloted by Doctor Zager. Tepig battled alongside Cilan's Pansage in Lost at the Stamp Rally! where they were battling against Subway Masters Emmet and Ingo's Chandelure and Eelektross while in the Battle Subway. After a hard battle, Tepig and Pansage got defeated.
In Evolution by Fire!, Tepig eventually reunites with its former trainer who abandoned and left him to starve way back in Accumula Town. Iris got mad for his mean and cruel behavior especially for abandoning Tepig. Don George finally settled to have both into a double battle. Shamus agreed to battle Ash with using both Emboar and Heatmor while Ash decided use Tepig and Snivy, who finally decided to join because of her concern for Tepig and dislike to Shamus for abandoning her friend.
At night, Tepig remembers the time he was released by Shamus back in the Accumula Town. Tepig could not forget about what happened until he met Ash and Snivy manages to snap Tepig out of his trance caused by his depression by slapping his face with her Vine Whip. She convinces Tepig not to give up the fight and don't let his guard down when facing Shamus which Tepig confidently agrees.
During the battle, Tepig ws initially unwilling to listen to Ash's commands whenever he looked at Shamus causing him to get hit by Emboar's Hammer Arm. When Shamus reveals his true nature by showing how happy he was to have eventually replace him with a new Tepig who eventually evolved into Emboar and he felt is much stronger than he is. Tepig was horribly surprised by this revelation after realizing how cruel Shamus was. Tepig was later hit by Emboar and Heatmor's Flamethrower and Fire Spin combination. By the time Snivy takes serious damage on both Pokémon, Tepig regains his composure after Snivy convinces him to work together to fight and Tepig confidently agrees as he hits both of them with Flame Charge but it didn't do a thing. Both Heatmor and Emboar unleash a combination of both Flare Blitz and Fire Spin to knock Tepig down only to be tackled by Snivy to take a direct hit which causes her to faint. Ash confidently encourages Tepig to keep battling both of Shamus' Pokémon in a handicap match as Cilan, Iris, Pikachu and an injured Snivy are counting on him. Seeing Snivy gets heavily injured and being supported by Ash and his friends, Tepig yells in a rage to evolve into Pignite where he demonstrates his true strength by hitting both Emboar and Heatmor with his newly learned Fire Pledge before defeating them with a more powerful Flame Charge. Shamus tries to take Pignite from Ash and rejoin his team just to make it on top. But since he now knows of his cruel nature, Pignite burns him with a Flamethrower declaring that he belongs to Ash. This causes Shamus to flee while he cursed him to remember this beating.
In Caution: Icy Battle Conditions!, Pignite was used against Brycen's Cryogonal and Beartic. He was able to take out Cryogonal by using Fire Pledge to aim for the center of the Rapid Spin but lost to Beartic when it used Aerial Ace for hiits Fighting-type weakness.
In Rocking the Virbank Gym! (Part 2), Pignite was up against Roxie's Scolipede and after his Flame Charge was blocked by Scolipede's Screech and its Sludge Bomb was intercepted by Pignite's Flamethrower, Pignite used the smoke to his advantage and hit Scolipede with Flame Charge before defeating it with Fire Pledge. However, Pignite got knocked out by Garbodor's Hyper Beam.
Pignite battled Dawn's Mamoswine in The Mystery of the Missing Cubchoo!. Pignite managed to dodge Mamoswine's Hidden Power by quickly jumping and then hitting Mamoswine with a very powerful Flame Charge. He managed to counter Mamoswine's Ice Shard with Flamethrower and Mamoswine used Take Down followed by Hidden Power. Pignite used Flame Charge and hit the Hidden Power head on, knocking both out and ending the battle in a draw. Pignite battled Trip's Serperior in BW094 in the final round of the Junior Cup. Although he had the advantage, he couldn't land a single hit, even after using Flame Charge multiple times to increase its speed, as Serperior was too fast and his body allowed him to easidly dodge. With Pignite being too tired, Serperior finished him with Frenzy Plant, knocking Ash out of the tournament and winning Trip the Junior Cup.
Pignite was used against Cameron in the quarter-finals of the Unova Leauge as Ash's third Pokémon. He faced Hydreigon, who previously defeated both Boldore and Oshawott. In this match, he also shows that he had learned Brick Break, which is super-effective on Hydreigon due to his Dark-type, and after a tough battle, he managed to defeat him, as Hydreigon was already weakened by Boldore and Oshawott. He then fought against Ferrothorn and won easily due to his type advantage, then faced Samurott, but he's too tired from the previous two fights and gets defeated by an Aqua Jet.
After Ash lost to Cameron in the Unova League, Pignite is later used to fight off Team Plasma grunts. But he is soon defeated by a Magnezone that also deflects Cilan's Pansage's Bullet Seed, as two of its seed shells manage to stuck inside of his nostrils.
This problem is soon revealed in Meowth, Colress and Team Rivalry!. Pignite hasn't ate his Pokémon food unlike the others as well as unable to use his Flamethrower. Ash did his best to make a jump with his Pikachu and Iris' Axew. Then Ash let his Charizard make a giant swing on Pignite but it didn't work either. Pignite was saddened about this until Iris got a piece of leaf grass to tickle inside of his nostrils making him sneeze the seed shells from Pansage's Bullet Seed to come off realizing Cilan's accident in the battle as Ash let him blow him with his Flamethrower which he succeeds followed by Charizard's own Flamethrower to make Ash burned up as both are seen unleashing their Flamethrowers as Pignite's are not strong enough than the former.
He and Charizard later teams up to fight Team Plasma grunts before Ash called them back when Doctor Colress turn the machine on them.
In The Pirates of Decolore, Pignite is playing with Pikachu at the ship before being attacked by the leader of the pirates revealed to be a Croconaw. After Croconaw, Ducklett, Octillard and Azumarill are revealed to be abandoned by their trainers when Meowth tries to translate their language, Pignite angrily tells them that the trainers aren't so bad but Snivy showing her dislike to the horrible trainers for abandoning them especially the pirates' actions. She proposes the battle if they win, the pirates will stop stealing someone's food. Pignite teams up with Snivy against Croconaw and Azumarill. Despite fighting at type disadvantage, Pignite gives a lot of effort to beat them when Snivy hits them with her Vine Whip and Leaf Storm as Pignite defeats them with Fire Pledge. When Team Rocket plans to capture the pirates, they were knocked by their Pokémon to blasted off in the sky by Pignite's Fire Pledge after Snivy hits both Woobat and Yamask with Leaf Storm.
In The Journalist from Another Region! Pignite was chosen for Sumo Tourmanant, Pignite challenged many opponents throughout the way until it faced off Rodney's Golurk for the finals & Pignite then lunged Golurk into the air emerged victorious & won the tournament earning itself the Focus Band around its head followed giving everyone the prize food as a token for friendship.
Pignite was sent to Professor Oak's laboratory after Ash ended his Unova adventure.
- Pignite is Ash's only Unova Pokémon who was never sent to Professor Juniper.
- Pignite is the first Fire-type Ash owned that didn't know Flamethrower when caught.
- Pignite is the only Fire starter evolved hasn't reached to its final stage followed by Ash's Quilava.
- Pignite also shares some similarities with Ash's Charizard and Infernape:
- All of them are Fire-types that evolved from Starter Pokémon at least once.
- All of them were abandoned by their original trainer because that trainer thought they were weak.
- All of them defeated their former trainers.
- All of them became among Ash's most powerful Pokémon, proving that their original trainers had been wrong about their strength.
- Ash saved their lives in some way. Charizard by keeping the flame on his tail lit. Pignite by feeding him because he was starving. And Infernape by catching him while he fell after Team Rocket grabbed him.
- Despite weighing 55 kg, Ash can easily lift Pignite, similar to his Larvitar.
At Oak's Lab
At Kukui's house
At Cerise Laboratory