Lucario is a bipedal, canine-like Pokémon, with fur that is predominantly blue and black. It possesses a short, round spike on the back of each forepaw, in addition to a third on its chest. It has red eyes, a long snout and ears. When its mouth is open, two pairs of pointed teeth, one in the upper jaw and one in the lower, can be seen. It possesses cream-colored fur on its torso, and blue fur on its thighs that resembles shorts. It has a medium length tail of the same blue color as well. It stands on its toes rather than on its entire foot. It has developed four black appendages that hang down from its head, which rise when Lucario reads or manipulates aura, a special energy that it senses. Lucario can study this energy to predict the movements of their opponents and track their quarry. They also have the power to manipulate this energy in an offensive manner, in the form of explosive spheres of energy. Lucario can understand human speech, and have been reported to communicate with humans through telepathy.
As Mega Lucario, its cream fur becomes longer, and its thighs slim down. It develops more spikes on the back of its paws, which have turned crimson. It also develops spikes on both of its feet, which have become crimson too. Its previously red eyes are now orange-colored. Its aura-sensing appendages grow longer, and two of them are tipped in crimson. Its shoulders also possess a spike each. Its aura heightens throughout its body, which formed black markings on its blue fur. In Kalos, Mega Lucario is believed to be the first discovered Mega Evolution. People call Mega Lucario's fighting style heartless due to it being bathed in combative instincts and not showing any mercy to any other opposing Pokémon.
Lucario is considered to be prideful, and is extremely loyal to its Trainer. It also seems to have a natural sense of justice. It usually lives deep in mountains very far from people to improve their skills. It is an exceptionally rare Pokémon. Lucario are primarily carnivores, hunting their prey in packs, though one Lucario was seen eating Berries and plants like roses. It has been seen eating chocolate, even though chocolate is not part of its natural diet.
Lucario debuted as one of the main Pokémon in Lucario and the Mystery of Mew. He belonged to Sir Aaron and was sealed away in his staff for a thousand years. Ash later released him during a festival and he helped guide him to the Tree of Beginning after Mew teleported Pikachu there. However, he sacrificed himself to save the Tree of Beginning.
Riley's Lucario debuted in Steeling Peace of Mind! at Iron Island. When Ash and his friends traveled there after being contacted by Barry, they found the local Steel-type Pokémon fighting brutally against each other and the other Pokémon on the island. When a crazed Aggron attacked Ash, Riley stepped in and had Lucario attack it with Close Combat. Despite being a Steel-type as well, Lucario wasn't immediately affected like the others of its type due to its strong aura.
A Lucario that can Mega Evolve into Mega Lucario appeared in The Aura Storm!, under the ownership of Korrina's grandfather Gurkinn. Gurkinn's Lucario was used in a battle against Korrina's own Lucario, but when Korrina's Lucario lost control when it Mega Evolved, Gurkinn's Lucario had to knock it out. It reappeared in JN025.
Lucario is a playable character for the arcade fighting game. Its moves include Force Palm, Bone Rush, Extreme Speed, and multiple variations of Aura Sphere. Upon entering Burst form, it Mega-Evolves and can use the Burst Attack Aura Blast.
In the Pokémon of the Year poll held by the Pokémon Company in 2020, Lucario was voted the most popular Generation IV Pokémon, receiving 102,259 votes. It was also the second-most popular Pokémon overall.
Lucario appears to be based on the Egyptian god of funerals and the dead, Anubis, who has the head of an African golden wolf. Anubis's role in Egyptian mythology was to judge the hearts of deceased souls based on their actions during their life. This resembles Lucario's ability to see a life form's aura. It also seems to be based on an Egyptian boxer. Boxing is a sport that is believed to have origins in Egypt.
The markings on Lucario's face resemble a mask. The rings around its shoulders may be inspired by iron rings used in martial arts. The four appendages on Lucario's head, together with the shape drawn by its mask (a bisected ring), may suggest inspiration from a khakkhara, which in popular depictions can respond to spiritual energies similarly to how Lucario's appendages act when it senses aura.
Lucario may be derived from the reverse of the Japanese transliteration of orichalcum (a mythical metal) or oracle (referring to its supernatural abilities involving aura). It may also involve lupaster (a subspecies of the Canis aureus), Cairo, pharaoh, lykos (Greek for wolf), luchar (Spanish for fight), or lucarius (Latin for (one) of light or luminary).
In other languages
From the reverse of orichalcum (a mythical metal) or oracle (referring to its supernatural abilities involving aura). May also involve lupaster (a subspecies of the Canis aureus), Cairo, pharaoh, or lykos (Greek for wolf).