Ever since his debut, even as a Treecko, just like Buizel, Snivy, Hawlucha and Greninja, Sceptile is cool, calm, collected, and serious, while holding a twig in the side of his mouth. Sceptile has an overpowering pride, similar to Buizel's, that he will defend at all costs from anyone or anything that damages him, most notably after being defeated by the wild Seviper before Jessie had caught it.
As a Grovyle, he was shown to tease the other Pokémon, especially Corphish, although it would always defend and protect them. Sceptile is also the one who stopped both Corphish and May's Torchic from fighting with just a single Leaf Blade. He was also in love with a Meganium until he realized Meganium is in love with a wild Tropius whom he defeated to gain Meganium's love.
When it evolves into a Sceptile, he does his best to save Meganium from Team Rocket but to no avail as his attacks are lost because of his broken heart. It later regains his attacks after getting recovered from being heartbroken.
As a Treecko
Sceptile was caught while he was a Treecko during the events of Trees's a Crowd, and was the second Pokémon Ash caught during his journey in the Hoenn Region. In its debut appearance, Treecko is shown sitting in the branch of the huge dead tree after he spits his twig on both Ash and Pikachu who accidentally came to their territory. Treecko demonstrated its abilities by knocking Pikachu with Pound. It reveals that Treecko has a dispute towards the elderly Treecko and its inhabitants who convinces it to move from another tree and Treecko rejects it. Ash and Pikachu helps it to restore the tree back to its former glory until all the wild Treecko including its elder are caught by Team Rocket. Treecko manages to knock off James' Cacnea with Pound causing Jessie to get bumped on the switch to release all Treecko including its elder and Pikachu. Treecko childisly taunts Cacnea long enough to distract it while at the Meowth Balloon with several lights. Eventually, Cacnea accidentally hits the balloon causing them to blast off. When the dead tree is about to rip in half, all of the Treecko tries to protect it until it was cut off to reveal a seed beneath the tree. Treecko finally challenges Pikachu in a battle but was defeated allowing Ash to capture it. Ash finally bid farewell to the wild Treecko and its elder and Treecko happily smiles to them after it joins Ash's side.
In A Tail with a Twist Treecko was a very stubborn fighter who never gave up in battle. This is also demonstrated when it was beaten by a wild Seviper before Jessie had caught it. Despite its near recovery, it trains heavily to break a rock from the falls using Pound and does an improvise move to break it. It manages to defeat Seviper with the same ability before Pikachu blasts Team Rocket off.
In What You Seed is What You Get? Ash trains Treecko to learn Bullet Seed by eating watermelons and spits all watermelon seeds. They are cornered by Natasha a watermelon master along with her Pokémon Grovyle and Slugma. Her Electrode disguised as a watermelon appear it notices Ash and the group are not watermelon thieves causing her mistake. Ash has a double battle with Natasha using Treecko and Corphish against her two Pokémon in her stead. Ash uses Treecko for an advanced training to learn Bullet Seed by fighting Natasha's Grovyle. As both Corphish and Slugma are down, the battle is interrupted by her Electrode who informs her about the watermelon thieves which happens to be Team Rocket using a giant Cacnea robot to steal the watermelons. They are soon attacked by Team Rocket's Cacnea robot with a multiple of watermelon seeds. Ash tells Treecko to watch how Grovyle hits them with Bullet Seed before its mouth were taped by Meowth. Treecko eventually learns Bullet Seed to cut off the sling of the basket to recover the watermelons but temporary as it allows the group to catch the watermelons followed by Pikachu to blast Team Rocket off with its Thunder Bolt. The battle of Treecko and Grovyle resumed as it tries to hit with its Bullet Seed at Grovyle but it was a lack of range and its practice and ends up being defeated by Grovyle making Natasha wins the battle. In the end, Treecko does not accept its defeat and it finally learns Bullet Seed when Ash and Pikachu gave him watermelons and it masters the technique properly by hitting them with efficiency.
In Exploud and Clear, Treecko evolved into Grovyle whilst battling a powerful Loudred, who later evolved into Exploud. He has a strong rivalry with Exploud and tries his best to stop Exploud from its own rampage. In the end, both Pokémon continues to challenge themselves in the battle.
As a Grovyle
Grovyle stayed with Ash when he travelled to the Battle Frontier. When Ash went up against a wild Onix who was also the Rock Pokémon King whose subjects had Brock, May, Max, Pikachu and the other Pokémon in cages, Ash chose Grovyle to battle Onix and in addition to the type-advantage, Grovyle's agility and speed gave him an edge in the battle and a single Leaf Blade was strong enough to cause the battle to go in Ash's favor.
Grovyle was used during his battle with Greta but was defeated by her Hariyama.
When Sceptile evolved, he lost his ability to use any of his attacks since his heart was broken when Meganium fell in love for a wild Tropius instead of him as a Grovyle. After seeing Meganium in danger, Ash's Grovyle evolved into Sceptile to try and protect him but to no avail. Sceptile was saddened after losing his abilities due to being heartbroken as Nurse Joy informs Ash about his condition.
As a Sceptile
Ruby and Sapphire series
Later, Sceptile finally regained all of his moves as well as the new and powerful Solar Beam attack. Sceptile used Solar Beam to defeat Spencer's Claydol. Sceptile was later used in an unofficial battle against Pyramid King Brandon and his Regirock when Ash was possessed by the King of Pokélantis. However, despite having a type advantage, he lost due to Brandon's strategy to lock-on targets. Ash used Sceptile going up against May's Blaziken in a battle & both of them tested off their power & both activated their abilities Sceptile activating its ability Overgrow while Blaziken activated its ability Blaze, the battle ended up in a tie and both Ash and May as the winners.
Diamond and Pearl series
Sceptile is an expert at the move Leaf Blade, his signature move. It's revealed to have learned Leaf Storm in the process, he was even able to defeat Tobias' Darkrai, who was considered to be virtually unbeatable, with a powerful Leaf Blade, becoming the only known Pokémon to have defeated the legendary Pokémon.
He battled against Tobias' Darkrai during the Sinnoh League tournament. Sceptile fought hard and took serious damage from its Ice Beam attack and then fell victim to Dark Void. But thanks to Ash's voice, he quickly woke up and finished it off with a powerful strike from Leaf Blade. However, Tobias' Latios easily defeated Sceptile with Giga Impact.
Black & White series
He appears, along with other Ash's Pokémon, in the opening scene of BW: Adventures in Unova. Sceptile also appears in The Dream Continues! among with all of Ash's Pokémon in a photo.
- Yūji Ueda (Japanese)
- Dan Green (English as a Treecko)
- Darren Dunstan (English 4Kids dubbed as a Grovyle)
- Bill Rogers (English PUSA dubbed as a Grovyle and a Sceptile)
- Sceptile is Ash's first fully evolved Grass-type starter.
- Ash's Sceptile is the only known Pokémon to have ever defeated Tobias' Darkrai.
- Sceptile is the only Hoenn starter Pokémon Ash caught, as Torchic and Mudkip were caught by May and Brock respectively.
- Like May's Blaziken, Ash's Sceptile was voiced by Darren Dunstan and Bill Rogers in his evolved forms.
- Out of all Ash's Pokémon, Sceptile holds the record for facing the most Legendaries at four, having battled a Deoxys in Pokémon Ranger-Deoxys' Crisis! Part 2 , Brandon's Regirock and Tobias' Darkrai & Latios.
- Sceptile shares some similarities as Ash's two first Water-type starter Pokémon.
- Like Ash's Squirtle who rarely wears its glasses as it keeps it in its shell, Sceptile is mostly seen with a twig on his mouth since he was a Treecko during battles even his evolution.
- Like Ash's Totodile, they use to have a crush on certain female Pokémon, namely Nurse Joy's Meganium to Sceptile and Trixie's Azumarill to Totodile. Unfortunately, the female Pokémon already have their respective boyfriend, namely Trixie's Golduck and the wild Tropius respectively, leaving both Sceptile and Totodile to move on.
- As seen in Ash's photo with all of his Pokémon in the end of Best Wishes series, Sceptile's current height is 7'3" which is the same height as Ash's Charizard.
At Oak's Lab
At Kukui's house
At Cerise Laboratory