A couple I saw while hiking in hong kong. Again, not exactly the most reassuring of signs:

And then there's a couple more I've seen around:

  • Warning: electricity (as seen on large transformers and such): Mr. Ped being hit from above by a spark the width of his head.
  • Danger: corrosive: A drop of liquid falling onto a hand, which already has a rather painful-looking dent in it. (One wonders why the owner of the hand did not withdraw it after the first drop hit.)