Try Rolling.

To the Death... or until he runs right past it and ignores it for the rest of the journey.

I beat it...

Fairly easy to kill, actually, as I recall. Just a bit time consuming. As with most Dark Souls bosses, there's a trick to it.

I accidentally killed him while trying to get the Drake sword and now I can't use him to farm souls.
Guess I shouldn't have used those large arrows.