In this video clip, The Joker traps Batman and Robin in a chimney and offers to let them out if they can stay afloat for one hour. He then fills the chamber with deadly gas, not water. This fits with the Joker as a twisted villain. He says to his henchmen, "turn the gas of, some passerby could get killed" once he thinks Batman and Robin are dead. The Joker is actually concerned with the lives of citizens. He is not a killer, he is an entertainer. In the beginning of this clip, he shoots his victims with some sticky silly string and says, "this is a stick up!" This is amusing, but not the antics of a killer. This attitude of the Joker fits with his first stage of his film career. He is not a murdering psychopath, he is an entertainer.