There are many animals in the biological world that are venomous, but not all venom is created equal. Some stings and bites are merely irritating; others can stun their victims slowly and unexpectedly. Then there are those stings that hurt — and that's putting it mildly. Here's our list of the 10 animals that deliver the most painful bites or stings in nature. While not every bite or sting from one of these creatures will kill you, the pain involved might have you wishing they would.