Lucario first appeared as a Riolu with its trainer, Cameron, to compete in the Junior Cup, but were disappointed as they found out it was over. Later, Cameron found out that he needed an eighth badge to enter the Unova League, and at the same time it was shown it did not take lightly it's trainer's act of forgetfulness, after that both him and Cameron head to the Humilau City gym along Ash and his friends.
Cameron and Riolu joined by Ash and his friends to travel to the Humilau Gym so Cameron could get his final Gym Badge. After getting lost and separated from Ash's friends, Riolu, Cameron, Ash, Pikachu, and Meloetta fled into a cave to shield themselves from the pouring rain and stayed there for the night. Later after meeting Marlon, Riolu stood alongside Ash, Pikachu, and his friends watching the gym battle against Cameron and Marlon, though Cameron was going to use it at first in the gym battle but he accidentally left it on the side, forcing him to use his other Pokémon battle in the fight. After a hard-fought battle Cameron won and Riolu was glad that he won and celebrated. Afterwards Riolu and Cameron later said goodbye to Ash and his friend as they would to see each other in the Unova League.
Riolu appeared again in the Vertress City Unova League. It was seen coming out of a tent along with Cameron near the building where the conference was being held, they revealed that they were camping for three days to come to the league early, but they found out that they had to register, and at that time, registration ended. Ash then rushed Cameron to the building to register, and the two trainers and their partner Pokémon were able to persuade Nurse Joy to let Cameron in.
After everyone had won the first battles, Cameron relaxed with his rivals in a sauna. Riolu jumped in, splashing Pikachu and Oshawott, causing the former to use Thunderbolt. The following day, Cameron battled Bianca and sent Riolu against Emboar. Emboar used Arm Thrust, but Riolu dodged the attack. Emboar attempted to attack with Hammer Arm, but got blown away by Riolu's Circle Throw, followed by Force Palm. Emboar managed to grab Riolu and toss it away, but Riolu managed to bounce away and take no damage. Emboar tried to use Flamethrower, but missed and, due to Riolu's Copycat, the attack was sent into Emboar's eyes. With Vacuum Wave, Riolu defeated Emboar.
Riolu and Cameron set up their tent on the ground of the Vertress City Unova League together. Nearing the ending of the day, it was destroyed by Iris as she saw Axew's hat on top of Cameron's tent, with Cameron in despair how everyone keeps ruining it, with Riolu patting Cameron on his head as he slumped to the floor. Cameron and Riolu battled against Kenton and his Gigalith and Riolu easily defeated Gigalith with Circle Throw.
Riolu was used as Cameron's final Pokémon against Ash to battle Pikachu, who had defeated two Pokémon before him. Despite taking virtually no damage from the previous fights, Pikachu was recalled for Unfezant. Riolu defeated Unfezant without being touched forcing Ash to send out his sixth Pokémon, Snivy. Though the battle went well for the two in the beginning, Snivy showed that Riolu was not invincible and started a comeback. Ash forced Snivy to dodge Leaf Storm so she could slam him into the ground with Vine Whip. Vacuum Wave did nothing, and when a second one came her way, she dodged with her vines and finished him with Leaf Storm.
However, when all hope seemed lost for Riolu, it miraculously evolved into Lucario and gained his strength back.
Snivy hit him with an Overgrow-powered Leaf Blade, but Lucario hit back with Force Palm. Snivy bombarded him with Vine Whips, but Lucario caught the vines and swung Snivy around. Though that wasn't enough to finish Snivy, his new Aura Sphere was, which left only Pikachu to battle. Pikachu started off with multiple Quick Attacks, all doing damage until Lucario caught the electric mouse and hit him with Force Palm. After a tie between Aura Sphere and Electro Ball, Lucario failed at landing both Force Palm and Circe Throw, and was damaged by a brutal Thunderbolt attack. After being struck by Quick Attack in midair, Lucario copied Pikachu's Iron Tail, and the two attacks collided. Lucario struggled to his feet, but readied an Aura Sphere, while Pikachu readied an Electro Ball. Mustering all of their strength, the attacks were launched, and the entire stadium lighted up from the epic collision. But this time, it wasn't a draw, and Lucario's Aura Sphere prevailed, shocking the entire stadium and knocking Pikachu out. In the semi-finals, it knocked out Virgil's Umbreon making both sides have only three Pokémon left. Lucario was recalled, but when all of Cameron's other Pokémon were defeated, he was stuck in a corner as Cameron's last Pokémon, with Virgil still having three Pokémon left. It tried to attack, but nothing could hit Flareon through Double Team, and since Lucario had gained the Steel type, it was wiped out by Flareon's super-effective Fire Blast, eliminating Cameron from the tournament in the Top 4. After having Casteliacones from Bianca, Cameron and Lucario bid their friends farewell and continued their journey.
Cameron and Lucario were seen in the Best Wishes! ending theme. Cameron continued his journey with Lucario and trained even more.
Voice actress and actor
- Lucario is the first Pokémon who is usually seen out of its Poké Ball to evolve in the anime since Misty's Togetic.
- Lucario is arguably Cameron's strongest Pokémon.
- Lucario is Cameron's only Pokémon that its species isn't originate from Unova.
- Cameron's Lucario makes an appearance in the Pokémon World Tournament download that is available for players of the Japanese Pokémon Black 2 and White 2 from December 3, 2012 to January 31, 2013. The tournament is based on the Vertress Conference in the anime, which is conducted under Single Battle rules. It is the 3rd strongest Pokémon in the games.
|Lv. 50||♂||Lv. -||-||Lv. ?||-||Lv. ?||-||Lv. ?||-||Lv. ?||-|
|Ability: Inner Focus||Ability: Unknown||Ability: Unknown||Ability: Unknown||Ability: Unknown||Ability: Unknown|
|Item: Lum Berry||Item: ?||Item: ?||Item: ?||Item: ?||Item: ?|