Scrambling for a last-minute Halloween costume? Looking for something a little more creative than that same Scream mask you've been wearing since 1996? Donald Trump wasn't a good costume in 2015, and it's a little too scary this year. Harambe and Dat Boi came and went already. But science news is always cool! So here are 13 Halloween costume ideas, ranging from darkly funny to downright terrifying, pulled from 2016 Popular Science stories.