When I was a kid the Batman TV show starring Adam West was the biggest thing on television and I didn’t miss an episode. (Same Bat-time, same Bat channel…)  One of the running gags on the show was that every tool and crime-fighting implement that Batman and Robin would use had the prefix “Bat” in front of its name, so they drove a Batmobile, climbed a Bat-rope and talked on a Bat-phone, and so on….

So of course, Marsupial Man’s gas weapon has to be Marsupial Mist.  It just sounds right to me.  And if you try to hear the line said in Adam West’s voice, it sounds even better….