red touch yellow, kill a fellow
red touch black, venom will lack

thats the one I heard....I t hink it was on a movie called "Ssssssst" Crazy movie about a guy injecting people with venom and stuff and turning them into snakes...his crowning achievement before he was killed was to transform one guy into a king cobra, only to be immediately killed by a loose mongoose.....was kind of a lame movie, but hey, I was young and it was cool....