Riolu

Riolu (リオル, Riolu) is a Fighting-type Pokémon and is the pre-evolved form of Lucario. A Riolu will evolve into a Lucario during the day with a high level of happiness.

Appearance
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.

Special Abilities
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 or Detect can not be learned by Riolu due to its inability to fully use the power of aura.

In Anime


Riolu has made an appearance in the Diamond and Pearl series in two episodes. This Riolu had the ability to use Aura Sphere at a very powerful level, unlike a normal Riolu. During the episode, it was stolen from its owner by a group that wanted to use its special abilities but it was recovered by Ash, who then returned it to its owner.

In Game
There is only one Egg from which Riolu evolves in the Pokemon Diamond & Pearl, which is given to you by a trainer called Riley upon completing the Iron Island maze and defeating the Galactic Grunts. It evolves through Happiness in the daytime (4am - 8pm).

Origins
Riolu's name is simply based off of Lucario's name, switching "Rio" with "Lu" and leaving out "Ca".

Trivia

 * Riolu is the only pure Fighting-type Pokémon whose evolved form is not a pure Fighting-type.