They can detect the species of a living being— and its emotions—from over half a mile away. They control auras and hunt their prey in packs. By catching the aura emanating from others, it can read their thoughts and movements. By reading the auras of all things, it can tell how others are feeling from over half a mile away.
Pokédex entry #448
Lucario in Pokémon GO
It's possible to hatch Lucario from an egg?
No, Lucario can't be hatched.
Which are Lucario’s strengths and weaknesses?
Lucario is a fighting and steel type Pokémon. fighting type pokémons are strong against normal, ice, rock, steel pokémons but weak against poison, flying, psychic, bug, fairy pokémons. They are not affected by ghost type pokémons. steel type pokémons are strong against ice, rock, fairy pokémons but weak against fire, ground, flying pokémons.