Decided to be Marceline! Highly recommend keeping a big had a fun sweater around for last-minute costumes I guess XD The fangs are the Scarecrow brand fans and I do really like them, you set them to your teet with this kind of dental putty/glue that sticks to the plastic of the fake tooth but not to your real ones and dries permanently into a cast of your tooth - so you can click them in and out really easily and they stay in pretty well! Its hard to talk with them and you can't obviously eat or drink with them for both safety and comfort reasons but they're perfect for pictures.
Also got pictures with my friend who was like... character perfect Draculaura (quite a few kids were VERY excited about her). If you saw on twitter my adorable gay son was also dressed as a vampire and they posted some pictures in response to my Marceline ones (DarkPactCosplay was Astarion).
I also used Trick or Treat as an excuse to give away a bunch of Magic bulk! We portioned some random cards (bulk foils and rares and stuff) into the cheaper deck boxes that I had left sitting around from the UltraPRO sponsorship days and gave them away to kids. Even if they just sort through the cards and look at the art, it was nice to have an option to give kids in addition or instead of candy! You could probably do the same thing with cards in zip-top bags too - maybe an idea for anyone next year looking to unload some cards.