In Lord of the Flies Piggy explains to Ralph that Jack can be very dangerous - if not to Ralph than to whom?

At the end of chapter 5: Beast from Water Piggy told Ralph how he felt about Jack, I quote... "He hates me. I dunno why. If he could do what he wanted--- you're alright, he respects you. Besides-- you'd hit him." Piggy also said... "I tell you what. He hates you too, Ralph---" And... "He can't hurt you: but if you stand out of the way he'd hurt the next thing. And that's me."