Brock's Steelix (Japanese: タケシのハガネールTakeshi's Haganeil) was the first Pokémon acquired by Brock in the anime, and is his main battling Pokémon in both the anime and games. It was given to Brock by his father, Flint.
Onix was first seen during Brock's Gymbattle with Ash at the Pewter Gym, where it was used against Pikachu in Showdown in Pewter City. Onix wasn't fazed by Pikachu's Thunder Shocks because of its secondary Ground type, and was easily able to subdue Pikachu with a Bind. Ash decided to forfeit the match because he couldn't stand to see Pikachu in pain. Onix was also used in Brock's rematch with Ash where it battled Pikachu once again. This time Pikachu's newly learned Thunderbolt attack was actually able to cause damage to Onix, though it was still not enough to defeat it. Onix once again had Pikachu in a Bind until Brock told it to stop because Brock didn't want to hurt Pikachu. Eventually Pikachu's Thunderbolt set off the sprinklers, severely damaging Onix because of its severe weakness to water. Pikachu took Onix down with one final Thunderbolt, but Ash chose to forfeit. Brock decided to give Ash the Boulder Badge anyway, and then joined him on his journey, bringing Onix with him.
Forming a staircase to help Ash and Brock escape
Like most of Brock's Pokémon, Onix received very little screentime in comparison to the Pokémon of the other main characters. This may have been due to its massive size.
Onix was sent out in an attempt to prevent Team Rocket from escaping with a Moon Stone in Clefairy and the Moon Stone. It tunneled through the ground and burst up to disrupt the escaping Team Rocket, and although it fought to a stalemate with Koffing, it held them up long enough for Ash and the others to arrive and save the day. In Pokémon Shipwreck,the trio were trapped in the upside down sunken St. Anne. Onix was used as a bridge and ladder to allow the group to reach lower levels of the ship.
Onix and Brock in the race
Onix was used as Brock's steed in The Flame Pokémon-athon!, during the big race. It managed to maintain second behind Dario and just ahead of a farmhand on a Rhyhorn. However, the race involved crossing a body of water, which the two Rock-type Pokémon were unable to cross, and Onix had to withdraw. Onix was noticeably upset by this, the only time it has been shown to weep.
Onix swatting Ash and Misty aside trying to dodge Totodile
In Sick Daze, it was revealed that Brock usually polished his Geodude and Onix as part of his Breeder duties. The dubious task of polishing Brock's Onix fell to Ash, who attempted to shorten his chore through use of his Totodile's Water Gun, which caused Onix to panic and earned Ash a reprimand from Misty. It was captured by Team Rocket, but was rescued by the arrival of Brock, Golbat and Pineco. It then used Rock Throw to send Team Rocket blasting off.
In Control Freak!, Jessie, in possession of an ancient Queen's mask and scepter, took control of Onix, along with Geodude and Pikachu. Team Rocket then beat a hasty retreat by ordering Onix to carry them out of the underground chambers. When Team Rocket fled, Onix was freed from the influence of the scepter. In Entei At Your Own Risk, Onix comically buried Psyduck in hot sand as it collapsed in the bed to relax. It later used its large, dense body to shield the group from Team Rocket's suction.
In A Family That Battles Together Stays Together!, Onix was used in a battle against Brock's mother and her Mantine in order to decide if the Pewter City Gym will become a Water-type Gym. Onix appears at a disadvantage, perched on a tiny island of rock in the middle of the lake. However, Onix leaps straight up, then dives down into its perch, starting out with Dig. With the rock destroyed, water floods into the new tunnel, which drains all of the water in the lake. Mantine flaps around and is unable to move anywhere, allowing Onix to come up underneath it and strike. While the attack caused damage it allowed Mantine to get up and fly. It then launches a Bubble Beam, which Onix counters with Bind. Lola tries to get Mantine to use Confuse Ray, but it fails. However, another Bubble Beam does work. Onix lets go of Mantine, who goes into a third Bubble Beam, but Onix defeats Mantine with Slam, allowing the Pewter Gym to remain a Rock-only Gym. Afterwards Brock ended up lending Onix, Geodude, and Crobat to his eldest sibling, Forrest, who took on the role of Gym Leader at Pewter City while Brock went to Hoenn.
Kanto Battle Frontier
When Brock returned to the Gym in Grating Spaces, Onix had evolved into a Steelix under Forrest's care. Steelix was shown to have learned Iron Tail and a powerful Dragon Breath attack during its time at the Gym. It was used in a Double Battle with Ash and his Donphan against Jessie, James, and their newly obtained Charizard and Aggron. The battle started out rough with Steelix being hit by Charizard's powerful Flamethrower. Donphan saved Steelix by attacking Charizard but was pushed back by Aggron's Mega Punch and Hyper Beam. Donphan continued to attack Charizard but was hit hard with Aggron's Water Pulse. Steelix then countered another Flamethrower with an Iron Tail and launched Donphan into the air over Aggron's Water Pulse. Donphan used the momentum to land a devastating Take Down attack on Aggron. The battle was stopped after Forrest discovered it was Team Rocket they were battling.
Steelix reappeared in When Regions Collide!, in which it battled against Kiawe's Turtonator. Turtonator started the battle with Flamethrower and Steelix countered with Gyro Ball to reduce the damage. It then rushed in and squeezed Turtonator with Bind, but was damaged by Shell Trap in the process. Recovering from the attack, Turtonator tried to use Dragon Tail, but Steelix burrowed underground with Dig and then struck Turtonator. Deciding that Steelix was too strong, Kiawe began to use his Z-Move, but stopped when Brock declared he was going all out as well. Revealing a Key Stone, Brock Mega Evolved Steelix into Mega Steelix. Kiawe and Turtonator retaliated with Inferno Overdrive; though it made a direct hit, Steelix was able to endure the attack, much to everyone's surprise. The two then collided with Stone Edge and Dragon Tail; Turtonator fainted as a result, making Steelix the winner.
Personality and characteristics
Like many of Brock's Pokémon, Steelix received very little personality development while it was on-screen, which was not often, most likely due to its size. However, it is very loyal to Brock as his starter Pokémon and reflects his personality quite closely. Like Brock, Steelix was very intimidating and serious in its debut appearance, mercilessly crushing Pikachu in obedience to its commands. Like Brock, its tough exterior hides a sensitive interior. Just as Brock gets emotional over women, Steelix has been shown to be morbidly afraid of water. In the big race in The Flame Pokémon-athon!, Steelix kept up a top three position until they hit a body of water and were forced to retire, causing it to cry in disappointment. When necessity forced it to expose itself to water when damming the Cinnabar volcano, it only permitted the tip of its tail to be soaked.
As a Steelix, its personality remains much the same. It was very happy to see Brock again and battled loyally alongside him.
Onix was the second Pokémon Brock used during his Gym battle against Red in File 1: Red. At first, it took massive and almost fatal damage from Red's Nidoran♂'s Double Kick, but was then able to defeat it with Bide. It then proceeded in defeating also Red's Spearow, Rattata, and Metapod in a quick succession, although the last managed to land a String Shot on it before being defeated. Red was left with only Charmander, and as it had also been significantly weakened while battling Brock's Geodude, both Trainers knew that the first one to land a hit on the opponent would win. Thanks to Onix's speed having been reduced by Metapod's String Shot, Charmander was able to outspeed the Rock Snake Pokémon and strike it with Scratch, defeating it and giving Red the victory.
Brock's Onix debuted in Onix is On!, where it took on Red during his battle to earn the Boulder Badge. As Red's otherPokémon were completely exhausted from the numerous Gym Trainer battles required to reach Brock, Red was forced to use his Pikachu, which he had only recently caught and was having difficulty connecting with. This lead to Pikachu making its own decisions during the battle, even at one point ignoring Onix and attacking Red instead. However, when Onix tried to attack Pikachu with Skull Bash, the Electric Mouse was able to shock Onix into pieces, making Red the winner.
Onix was used again in Capital Kabutops in an exhibition match against Jasmine and her Steelix, who was wearing a layer of rock over its steel body to disguise itself, causing everyone to believe it was an Onix. As the two constricted each other, Onix took damage due to Steelix's much harder body, and the Iron Snake's outer coating began to chip and fall off. Exposed as being a fraud, Steelix broke out of its disguise and revealed its true identity. Onix was then quickly taken down by Steelix's Crunch.
A † shows that the move was used recently, unless all moves fit this case or there are fewer than five known moves.
In The Electric Tale of Pikachu manga
Onix in The Electric Tale of Pikachu
Brock's Onix briefly appeared in Play Misty For Me, taking part in the Gym battle between Ash and Brock, eventually getting defeated. It reappeared in Haunting My Dreams, where it was used to battle the giantHaunter known as the Black Fog. However, like almost every other Pokémon taking part in the battle, it ended up being defeated.
In the Pocket Monsters HGSS Jō's Big Adventure manga
Brock's Onix appeared in Bring Down the Powerful Opponent Onix!!, during Red's battle with Brock. After witnessing Green and his Charmander being tossed out of the Gym, Clefairy was initially too afraid to face Onix in battle and attempted to flee, but later gained courage to fight after learning that his cousin Pikachu (Pocket Monsters) was part of Brock's collection, which infuriated Clefairy. During the battle, Clefairy tried to use an assortment of tricks to win the battle, which only prolonged the fight. Eventually Clefairy led Onix around a ceiling column, trapping Onix as it became entangled around it. Onix managed to free itself and attempted to crush Clefairy by wrapping its tail around him, but stopped after Clefairy cunningly drew his picture onto Onix's tail, which confused Onix and caused it to chase after its own tail. This made Onix dizzy, and Clefairy subsequently knocked it out by smashing the fallen pillar onto its head, thus winning the battle.
In the Pokémon Zensho manga
Onix in Pokémon Zensho
Satoshi battled Brock's Onix in Pewter City, using his Charmander. Although initially having trouble against the huge Rock-type, Charmander eventually won the battle by chopping off the horn on Onix's head, defeating it.
Related cards 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.