Dark Souls Remastered | Great Club location in Blighttown

Those guys throwing boulders are Infested Barbarians and can be hard to kill, especially two at once. You don't have to kill them to get the loot. There are two different types of Infested Barbarian. There's the kind that swings a club and they're easy to kill, not to be confused for the ones throwing boulders. You can read about the ones throwing boulders here:

https://darksouls.wiki.fextralife.com/Infested+Barbarian+(Boulder)

You can read about the Great Club here:

https://darksouls.wiki.fextralife.com/Great+Club