The only thing people love more than fun costumes on Halloween is trivia about said costumes' inspirations. By learning more about what you're going as you're not only enriching your mind, you're arming yourself with vital ice-breakers, chit-chat and banter-fuel that will definitely make you the life of the party.
Zombies: Did you know that the zombie-as-pandemic trope is relatively new? Back in the day, zombies were the victims of voodoo corpse reanimation and could be counted on to do things like manual labor for their masters (not exactly the shuffling masses of The Walking Dead). And even further back in the day, Zombie was the name of a snake god in West Africa. While we're at it, you should probably peruse our Topic Page on Viruses to see why a disease transmitted through biting probably wouldn't achieve the overnight apocalyptic effects portrayed in movies.
Any of the X-Men: Can we be real for a minute and question why all the mutants in X-Men have superhero abilities? It's all flying and setting things on fire, when we could really use a gene for successful conflict mediation, or something to make speed-reading prolific throughout the gene-pool. Anyway, we all know that gamma and X rays can cause mutations, but did you know extreme temperature changes, or certain mutagenic chemicals (such as nitrous acid, nitrogen mustard) can also cause inheritable changes to genes?
Frankenstein's Monster: We won't sit here and lecture you on how going as "Frankenstein" for Halloween means dressing up like a scientist (although we could, and we probably have in the past). Did you know that the monster's current portrayal as a bumbling semi-verbal hulk bears little resemblance to Shelley's creation, who spoke fluent French and was more limber and flexible than any human.
Elsa from Frozen: Parent's might be upset about their kids pressuring them into buying pricey Elsa costumes this year, but they need to let it go. Did you know that the record for snowfall in the US is 1,140 in. at Mt. Baker in Washington state during the snow season of 1998-99? Did they want to build a snow man that year? Probably not.
Cheney's dogs dressed for halloween, By White House photo by David Bohrer [Public domain], via Wikimedia Commons, http://commons.wikimedia.org/wiki/File:Cheney%27s_dogs_dressed_for_halloween.jpg?fastcci_from=7114332