Go in with a Sharpie and change the sign: "We kill Johnny Depp Chameleons". Stupid parents buy anything their kids want.
Petstore employees hate me. If I overhear some parent wanting something inappropriate for their small child, I'll give the run down on why the animal is a very poor choice. I do it all the time, *especially* where parrots are concerned. Bunnies, chameleons, certain other reptiles ... I even do it while staff are trying to push the virtues of the animal. What are they going to do -- kick me out? I hope I've saved some poor creature with that technique.