lol, its funny this has been mentioned. I got a cat a few months ago and called her Bellatrix! I know alot of people hate her, but she is my favourite and completly mad, she never has a dull moment throughout the whole series!
I want an owl. My kids and I each have a tiny flock of stuffed ones. We started when we read the first book. yes we have elderly stuffed owls. I have mine by my pillow, yes my dear hubby thinks i'm nuts but he keeps the bar open anyway!
I don't think house elves qualify as pets. A thestral would be a challenge, especially feeding them, as they like raw meat. Baby mandrakes grow up, you know! better get really GOOD earmuffs and tough gloves. I'm still leaning toward an owl-a little one like Pigwidgeon.