Instead of using Halloween to try and look as slutty or as cool as possible, why not try to flip the coin and make yourself the funny one for a change?
I guarantee mosre people would want to approach you and start a conversation - look at it as a chance to gain new relationships and experience something a bit different.
You have a kid, but still want to have fun? No problem!
You don't want to leave your puppy at home?
You want to be interesting? Or at least look interesting?
You'd like to look hot, but also convey a message?
Or, if you're getting really desperate, you can always go the obvious route: