I was gonna say gardevoir, but all the pics are hentai-ish, and I threw up a little when I saw them. I also realised she was hollow, which would be... wierd. So i went for the best pokemon EVAR!
http://pokesafari.deviantart.com/art/Munchlax-Anime-Style-39419665
all credit to the artist, as he might be pissed as I used this pic, but seriously, munchlax is cute, furry, and eats pretty much anything, so hell be easy to feed.
Oh, and hes small (for a Mon) and thus can live in the house (although the food cupboards may have to be locked up.) and whenever he evolves, just press B.
cheers
rosac