Ash's Sceptile (Japanese: サトシのジュカイン Satoshi's Jukain) was the second Pokémon caught by Ash Ketchum in the Hoenn region. His voice actor in Japanese is 上田祐司 Yūji Ueda and his English voice actor is Bill Rogers. As a Treecko, he was voiced by Dan Green in English. As a Grovyle, he was voiced by Darren Dunstan (4Kids Entertainment dub) and by Bill Rogers (Pokémon USA/TAJ Productions dub) in English.
Treecko was caught in the episode Tree's A Crowd! after Ash helped him in trying to save his old tree home; this event was followed by a battle with Ash's Pikachu, and Ash caught him as a result of that battle. Treecko evolved into Grovyle in the episode Exploud and Clear while in the middle of a battle against Guy's Loudred. He evolved into Sceptile in Odd Pokémon Out in a fight against Team Rocket. Until Cutting The Ties That Bind, Sceptile lost his ability to use attacks due to a broken heart. He regained his attacks in the above-mentioned episode
and was used in Ash's battle against Spenser in the next episode, Ka Boom With A View.
Sceptile has since become one of Ash's most powerful Pokémon, even strong enough to hold its own in battle against certain legendary Pokémon. It is exceptionally fast and a good jumper. Unlike others of his species, Sceptile keeps a twig in his mouth much like a 番長 banchō, juvenile gang leader, a character type that was common in manga and anime in the sixties and early seventies. He is also a bit of a loner, and can often be seen sitting solitary on the branch of a tree, resting or looking at the sky. Both of these habits are carried over from when Sceptile was a Treecko. Despite this, Sceptile is a competitive battler, almost never turning down a fight. Sceptile was one of five Pokémon that Ash took with him on his journey to the Battle Frontier.
Ash left Sceptile at Professor Oak's lab before setting off to Sinnoh.