Riolu is a black and blue, dog-like Pokémon nearing two and a half feet. Its appearance is similar to its evolved form Lucario, though there are some differences. Its legs and torso are colored black while its head, lower body and tail are blue. Riolu have large, rounded bumps on the backs of its forepaws, placed in a similar fashion to Lucario's spikes. Riolu also have a black "mask" with two black appendages on either side, and red eyes.
Riolu are sensitive to a special type of energy called Aura as Lucario is. Riolu's evolved form, Lucario, can use these waves for attacks, tracking, or to predict future moves. However, Riolu does not have the full potential of these powers, using them as described in ripples rather than waves. Moves such as Aura Sphere can not be learned by Riolu due to its inability to fully use the power of Aura. There is at least one exception to this rule, however.
Riolu evolves into Lucario when you level it up during the day with high friendship.
|Diamond/Pearl||Egg on Iron Island||One|
|Platinum||Egg on Iron Island||One|
|Black 2/White 2||Floccesy Ranch||Rare|
|Sun and moon||Poni Grove||Rare|
|Sword and shield||Giant's Cap||Rare|
In the anime, Riolu has made an appearance during Pokémon Ranger and the Kidnapped Riolu! Parts One and Two, which aired as a one hour special commemorating the release of Pokémon Ranger: Shadows of Almia. This Riolu had been trained to use Aura Sphere and was unnaturally strong. It was taken away from its owner by a group that wanted to exploit it but Ash and co. returned it, with Kellyn's help. This Riolu developed a strong bond with Ash.
Cameron has a Riolu that battled in the Unova league and evolved into a Lucario and defeated Unfezant, Snivy and Pikachu but lost to Virgils Flareon.
Korrina has a Riolu that evolved into a Lucario.
Ash's egg hatched into a Riolu and then went on to attack other pokemon with its vacuum wave until Ash managed to convince Riolu to join Ash. Currently it is with Ash's and Go's other pokemon at the Cerise Laboratory. When Riolu went with Ash to the Kalos region it admired Korrina's lucario and watched Ash defeats her Lucario.
In the Pokémon Adventures manga, Maylene has a Riolu. It is seen using Drain Punch against Pearl's Monferno, who Platinum borrowed in order to fight her. Then, when Diamond's is traveling alone, he is given an egg by Riley, which eventually hatched into a Riolu. In Pokémon Diamond and Pearl Adventure! Hareta gained a Riolu egg in Serious Training on Iron Island which hatched into a Riolu later on in that chapter.