This avatar, currently being used by MobileRead member cryzed, reminded me of an insane cat I once met.
It was in San Francisco in May 1968. I walked into a head shop and found a cat sitting on one of the shelves. I smiled, said something like 'hello, kitty' and raised my hand to pet it. Immediately the cat jumped up and ran to the edge of the counter, barred its teeth, hissed, and challenged me to a fight. No, it didn't say, "Hey, buddy, you wanna' fight?" but its intentions were unmistakable. I've seen cats that weren't in the mood to be bothered make their preferences known, and I've seen cats that didn't know me run from me, but this is the only time in my life I've ever seen a cat that did everything but mutter the actual words, "What are you looking at, bub? You want me to rip you head off and stuff it where the sun don't shine?"
The store's owner explained that the cat had been like that ever since someone slipped it a tab of acid.