Ooh, this is a good one.
What's your favorite legendary dog/cat?
Since Lucario is more of a rare pokemon and not legendary, i would have to say Mewtwo. I have like 4 Mewtwos that i got from migrating from two firereds, a leafgreen, and a heartgold, the one from leafgreen being the one i had longest. Mewtwo used to a top player in my team back in leafgreen and was one and still is of my favorite pokemon. I remember just using Mewtwo for the entire leafgreen elite 4 and champion once he reached Lv100. Using Thunderbolt, Flamethrower, Ice Beam, and Psychic, he would always have a move for all types of pokemon. Yeah so my favorite legendary cat/dog is Mewtwo. I was rambling wasn't I? Oh well.