Half Blood Prince Theory

[Brent]

No: HPFGUIDX 107653

I don't think it can be Tom Riddle because the same reason he would 
be considered a prince would make the same true for LV.  If his 
mother had some noble blood making him a prince that would still hold 
even if he changed his name. 

The Hagrid idea is interesting though I don't think it will be him.  
I still think it will be a new character.  I'm thinking it will be 
some kind of half Bastilite (the king of snakes) creature or 
something like that.