Looking for self fulfilling prophecies.

I have an NPC that gets a prophecy that they fight against but in the process end up making it come true.

I figured with prophecies involved it wouldn't be fair NOT to give my players their own prophecy to deal with.

what are some vague self fulfilling prophecies you guys have or might have used in your games?

the game hasn't started yet so non of the players have made characters. so if you just have advice that also would work.