Cameron's Lucario

Cameron's Lucario is the first pokemon Cameron was revealed to have and his main pokemon who is ussually seen out of it's Poké  Ball.

In the anime
Riolu first apppeared in BW095 along it's parthner Kotetsu to compete in the Junior Cup but were dissapointed as they found out was over. Later in that episode Kotetsu finds out that he needs an 8th badges to enter the Unova league, and at the same time it's shown it doesn't take lightly it's trainer's act of forgetfulness, after that both him and kotetsu head to the Humilau City gym along Ash and his friends.

In the next episode Cameron and Riolu are 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 agaisnt kotetsu and Marlon, though Cameron was going to use it at first in the gym battle but he accidently left it on the side, forcing him to use his other pokemon battle in the fight. After a hard fought battle Kotetsu won and Riolu glad that he won, afterwards Riolu and Kotetsu later say goodbye to ash and his friend as they to see each other in the Unova League.

Riolu appered again in BW105 in the Higaki 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 to sign in for the league early but they found that they were late again, Ash then desperetaly drags Cameron to the building to register.

In the games
Cameron's Lucario makes an appearance in the Pokemon World Tournament download that is available for players of the Japanese Pokémon Black 2 and White 2  games           games from December 3, 2012 to January 31, 2013. The tournament is based on the Higaki Conference in the anime, which is conducted under Single Battle rules.

Trivia

 * Kotetsu's Lucario is the only one by far in the whole pokemon series to have evolved from a Riolu unlike other Lucario's who were already seen in their full evolved form.
 * Lucario is the first pokemon who is ussually seen out of it's pokeball to evolve in the anime since Misty's Togetic.
 * The Japanese airdate of BW107 which features Riolu's evolution fell on the same week as the English airing of BW095: Goodbye, Junior Cup - Hello Adventure!, its debut appearance.