I once tried stealing from a Kecleon in the original PMD. My plan was to steal the stuff and quickly use an Escape orb to escape completely. I failed: the Kecleons used their superpowers to prevent the usage of that orb (or something like that :P)! Well, needless to say I was wiped out.
Recently, in PMD2, I had just been in a Kecleon shop but hadn't bought anything when I stepped in an explosion trap. Well, what a pain, but at least it didn't kill me, I thought. Then suddenly, one of my teammembers fainted! I was all "what just happened?" I realized too late: the Kecleon was attacking my Pokemon! The trap must had hurt it as well and it went on rampage. It wiped my whole team out with just couple of regular attacks. That taught me to never mess with Kecleons, even by accident.
Recently, in PMD2, I had just been in a Kecleon shop but hadn't bought anything when I stepped in an explosion trap. Well, what a pain, but at least it didn't kill me, I thought. Then suddenly, one of my teammembers fainted! I was all "what just happened?" I realized too late: the Kecleon was attacking my Pokemon! The trap must had hurt it as well and it went on rampage. It wiped my whole team out with just couple of regular attacks. That taught me to never mess with Kecleons, even by accident.