Jasmine was first seen with a Steelix in Nerves of Steelix!, where it rescued Ash's Pikachu after he had been kidnapped by Team Rocket. It easily managed to knock over their mecha after Brock and Janina's Onix had failed to do so. It then disabled the mecha with its powerful jaws, and once Pikachu was safely back in Ash's possession, sent Team Rocket flying with a powerful Iron Tail. This Steelix was used again later during the second round in her Gymbattle against Ash. It was put up against Ash's Pikachu, however the Mouse Pokémon was fatigued from his previous battle against Jasmine's Magnemite. Additionally his Electric-type moves had no effect on Steelix, a Ground-type, neither did his Quick Attack do much damage to Steelix's hard body. After a valiant effort, Pikachu was easily defeated by Steelix's Iron Tail.
Steelix in its debut
Ash then sent out his Cyndaquil to battle against Steelix. Despite being at a type-disadvantage, Steelix managed to defend itself against Cyndaquil's Flamethrower through use of its Sandstorm and then disappeared from the field by burrowing underground. After resurfacing, its attempts to attack the Fire Mouse Pokémon failed as Cyndaquil easily managed to dodge them all. It then reused its Sandstorm and Dig combination to defend against another Flamethrower. After continuously failing to hit one another, Ash had Cyndaquil use Smokescreen and use Steelix's holes to hide in. Once the smoke had been cleared, Cyndaquil managed to land a direct hit with Flamethrower from its hiding place. Jasmine then had her Steelix use Iron Tail on the ground, causing the tunnels below to cave in, forcing Cyndaquil out of the hole. After hitting Cyndaquil with Iron Tail, it looked like Steelix had won. However, Cyndaquil managed to recover and avoid being knocked out through use of Smokescreen. Steelix then used Sandstorm to defend against Flamethrower, however this tactic inevitably failed in the end as Steelix's Sandstorm was ignited, surrounding Steelix in a tornado of flames, knocking out the Iron Snake Pokémon, earning Ash the Mineral Badge.
Jasmine's Steelix debuted in Capital Kabutops! wearing a layer of rock over its steel body, causing everyone to believe it was an Onix. It battled against Brock's Onix, and as the two constricted each other, Onix took damage due to Steelix's much harder body and Steelix's outer coating began to chip and fall off. Exposed as being a fraud, Steelix broke out of its disguise and revealed itself to be Steelix. It then easily took down Brock's Onix, and Jasmine explained that her Steelix also used to be an Onix until it evolved. After Professor Oak explained that Steelix has yet to be officially classified, Jasmine explained that because of its rarity, she hid Steelix's identity so it wouldn't be exploited.
After Tyrogue confessed his feelings to Jasmine by giving her flowers, Steelix rose out of the ground as soon as Jasmine was about to accept the gift. As Steelix was after the same thing, both he and Tyrogue fought for her. As a result, Clefairy gave them some challenges in which they drank some milk, ate some snack balls and gag battled in the end.
However, Jasmine stopped the fighting between Steelix and Tyrogue. She took out a machine to determine who was compatible. As the machine pointed to Tyrogue and then to Pikachu, Steelix slammed his head onto the machine in frustration.
In the TCG
Jasmine's Steelix is featured in the TCG as one of Jasmine's Pokémon. The following is a list of cards named Jasmine's Steelix.
Jasmine's Steelix Cards listed with a blue background are only legal to use in the current Expanded format. Cards listed with a silver background are legal to use in both the current Standard and Expanded formats.