I didn't see the sting of a puss caterpillar, Megalopyge
in Justin's list. I guarantee you he hasn't been stung by one or I promise you it would have been included.
Puss caterpillars are apparently encountered from Florida to Texas in the US, and a number of people go to the hospital every year after being stung by them. While living in Trinidad and Tobago (Caribbean), I reached for a piece of fruit in a tree and a beautiful golden caterpillar fell from a branch and grazed my arm. The sudden, intense pain felt somewhere between burning fire and corroding acid. It traveled up my arm into my elbow and shoulder joints and did not subside for 7 hours. Ice, ibuprofen, stronger pain killers; nothing helped. My heart raced and I really was afraid I might die.
The literature says that the larger the caterpillar, the more venom they carry in their stinging hairs. The US version is said to grow to around an inch long. The one that stung me was 2 1/2 inches long - over twice as long as what any of the experts have described, that I've been able to find. I showed it to elders in the Caribbean village where I lived, and none of them had ever seen one before.
I've took a picture of it next to a ruler. Since I apparently discovered this subspecies, I get to name it: Megalopyge DiabolicalAssHoleai