[quote=Lalliman]
I just rewatched the fight on youtube and he can't be much bigger than 8'. Artorias might be bigger, but he's unparryable.Then again that might not be because of his size but by virtue of being a boss. None of the bosses are parryable except Gwyn for some reason.
[/quote]

Well, maybe Gwyn's parry able to keep up the lore that's built around him. After having his soul burn in a flame for so long, and being reduced to a powerful hollow, maybe he just became that weak?