Joker 2 has players taming wild Dragon Quest beasts and training them in turn-based battles. It has over 300 of the series' signature critters, and can even obtain monsters via Tag Mode with Dragon Quest VI and IX!
Speaking of other Dragon Quest games, Nintendo is really serious about this Dragon Quest thing, huh? It published Dragon Quest IX last year, then VI early this year -- and Dragon Quest characters are in both Mario Sports Mix and Fortune Street (also announced at this E3). We never expected to see any Western publisher care this much about Dragon Quest, much less Nintendo.