(He) looked rather like an old lion. There were streaks of grey in his mane of tawny hair and his bushy eyebrows; he had keen yellowish eyes behind a pair of wire-rimmed spectacles and a certain rangy, loping grace even though he walked with a slight limp. that is the description of the half blood prince we should think about who that looks like.

Headless Hunt: Thanks for this quote from the JKR site. I've copied and pasted it YET AGAIN!!! Can you believe how many of these 'Who's the HBP?' threads are posted??!!!

Now the pressures on! You've opened up yet another 'HBP?' thread but now we have to make this discussion different! Go somewhere different from ALL the others!! Come up with names and theories that none of ALL the others on this site and ALL the other chat rooms have come up with!!! Are we up to the challenge?!
I CAN"T HEAR YOU!

Ok we know HBP is not:
Crookshanks (He's a half Kneazle not an animagus)
Voldemort (Jo's said no!)
Harry (Jo's said no!)
Hagrid (Jo's said no!)
The description doesn't seem to fit any student/ kid.

So... ???