One time i was helping my mother with yard work, and i had a motorized weed eater. I hit a big patch of what i thought was simple ground cover, but it turned out to be poison ivy, and i totally vaporized it, lol. It got on me, and i had poison ivy for 4 months! I had to get a shot before it went away, they were worried it was going to get in my lungs and stuff.
Out of all the villains in the Batman universe, i think Poison Ivy's the most dangerous to me.