Valestra's Death
Is this the only time we see Joker actually kill someone with Smilex gas in the animated storyline? (Well, we didn't actually see it, but we did see the aftermath) I remember him poisoning people in "Laughing Fish", but I don't think there were any deaths. Correct me if I'm wrong.
"Sheldon, if you say ONE WORD, I swear to God you'll choke to death on my fist!!"