Snape, of course

[Catlady (Rita Prince Winston)]

Pippin wrote in http://groups.yahoo.com/group/the_
old_crowd/message/1712 :

<< But he saved Harry's life, when it's clear that he thinks it 
would serve the little twerp right if he got himself killed. And 
I'm pretty sure Snape didn't know about the prophecy. Why should
anyone tell him? >>

Surely Dumbledore must have told Snape that HP is the only one who can
defeat LV,  because he needs Snape to help protect HP at Hogwarts.
Snape saved HP's life when he'd rather transfigure HP into a worm and
step on him, because Snape puts an even higher priority on defeating
LV than on hating Marauders.

Kneasy wrote in http://groups.yahoo.com/group/the_
old_crowd/message/1718 :

<< Has anyone explored the possibility that Voldy is Snape's 
father? >>

Yes, including a long-ago fanfic in which Lily and Sevvie were
Voldemort's twins, put in foster homes at birth, who met at Hogwarts
and fell in love. Until learning of their prior relationship. 

But (as you later mention) JKR's website has told us that Voldie has
no children. 
http://www.quick-quote-quill.org/articles/2004/0304-wbd.htm
Q: Has Voldermort any children?
JK Rowling replies -> No. Voldemort as a father... now that's not a
nice thought. >>

In my own private Potterverse, while Tom Riddle might have casually
begotten some children (as you later suggest), Lord Voldemort *could
not* have begotten any children because he gave up sexual organs as
well as sexual desire when he turned himself into an immortal
snake-man. I feel certain that he had turned himself into an immortal
snake-man (no longer having any visible resemblance to TMR) before he
started his terrorist activities. 

For your theory, the question is, how long before? The wizarding 
world had been terrified ('had precious little to celebrate') for
'these eleven years' at Halloween 1981, putting the last previous
celebration in 1969 or 1970. How many terrorist attacks did LV and 
the DEs make (over how long) before the wizarding general public
stopped regarding them as fluke events? How long before that was his
physical transformation?

Kneasy wrote in http://groups.yahoo.com/group/the_
old_crowd/message/1729 :

<< Mind you, switching from Voldy to DD as proud papa to Snapey is
a bit startling. Whatever. That's what we're here for, isn't it? >>

Make'em both true. Sevvie's ma is Dumbledore's (grand*)daughter and
Sevvie's da is the handsome, talented, charming Tom Riddle. It could
even be that he seduced, impregnated, and abandoned DD's (grand)
daughter, not for relief of physical needs, but on purpose to insult
DD.

*Dumbledore, 150 years old at book time, 120 years old when Sevvie's
generation was born, around 90 years old when Sevvie's mum's
generation was born ... he could have great-to-the-n-th
grandchildren. 

<< But who's his mum?
Knowing how Jo constructs her plots, it's probable that the name has
already appeared somewhere in the books, hence my contention (in
the Black Widower hypothesis) that Snape was paired with Florence.
So who could it be? McGonagall? Mrs Figg? Poppy Pomfrey? Doris
Crockford? The mind boggles. >>

Mrs Norris? She turned into a cat to hide from ... not Grindy, the
timing is wrong...