Lucario is one of 62 fighters currently participating in Super Smash Bros., having been part of the competition since 2008.
Biography and personalityEdit
This is in fact the same Lucario from the eighth Pokemon film, Lucario and the Mystery of Mew (see here for more info). Although he had originally died in that movie, he was resurrected by Zelda when she realized he could make a great fighter for Smash. In this regard, Lucario wanted his master, Sir Aaron, brought back as well. She complied.
As established in the movie, this Lucario is actually quite fond of chocolate, having been introduced to it by Max Maple. Lucario has a secret chocolate stash and will stop at nothing to keep others out of it. Sir Aaron will often make special trips to pick up other chocolate-based items that Lucario enjoys, such as Canfield's Diet Chocolate Fudge Soda, as well as Hershey's Sundae Pies from Burger King (which has a history with the Pokemon franchise).
Both had sacrificed themselves during the eighth Pokemon movie, during which Lucario was an independent Pokemon. Lucario had initially lost respect for Sir Aaron upon his sacrifice, but as time went on, Lucario understood why he did it. So when both were brought back to life (and not the "wake me up inside" kind of doing so), Lucario asked Sir Aaron to become his master. He agreed to do so, and the two work together in making Lucario a strong Smasher.
See here for more info.