Nothing can breed with Riolu because it is classified in the Pokémon programming game data as a 'Baby Pokémon' and Pokémon that are classified as Baby Pokémon are not capable of breeding with other Pokémon in order to create Pokémon Eggs. Riolu's evolved form of Lucario however can breed with other Pokémon.
No. Riolu is classified as "No Egg Group." However, you can evolve it and breed it with Field or Human-Like pokemon.
riolu evolves when he is really happy
Rioulu is a baby Pokemon so it cannot breed with any Pokemon.
Riolu is considered a 'baby' Pokemon like Smoochum, and Pichu. It cannot breed until it evolves.
yes it can because ditto can transform to a riolu EDIT: No, because Riolu is considered a "baby" pokemon, such as Elekid and Pichu, and cannot breed. However if you breed a Lucario and a Ditto, that would work.
you can breed a lucario with a ditto or go to iron island and get a egg from riley
Yes it is possible.
Riolu evolves at maximum happiness, not at any specific level.
To breed a Riolu, you need to put a Lucario/Riolu with a Pokemon of 1. The opposite gender, and 2. Sharing an Egg Group with Lucario/Riolu into the Daycare Center. (Those Egg Groups being Ground and Human Shape) OR Put a female Riolu / Lucario with a Ditto in the Daycare Center Following either step, an egg will be produced. Walking/Biking with this egg in your party will hatch it into Riolu. (6656 Steps, which can be halved by bringing a Pokemon with either Flame Body or Magma Armor as it's ability)
4567
it evolves at lelvel 89
train it til lv. 30 or up