I just love to duck around with the final boss of fire emblem awakening. (Changed from assassin to their, etc.) He basically couldn't hit me at all.
Probably Skeleton from Terraria. Pretty much any pre-hardmode bosses in that game. All the hardmode enemies are assholes.
No, but still, FNAF has no boss fight. You can put something on its hardest difficulty, but that doesn't make it a boss fight, now does it?
Difficulty doesn't matter. A boss fight can be very easy, but it's not a normal level, it's still a boss fight.