To remove trailing commas in JSON: Find: (.?)(,)(:?\s]|\s*}) Replace: $1$3
Or: how to get every monster into Roll20 with ease.
Go to https://github.com/astranauta/5etoolsR20/raw/master/5etoolsR20.user.js. Follow the instructions for use: install Greasemonkey/Tampermonkey, install the script, then you’re good to go.
Open the Roll20 game you want to import the monsters into.
With the userscript installed, go to the gear icon and hit Import Monster. Use the following URL for the prompt that pops up: https://raw.githubusercontent.com/astranauta/astranauta.github.io/master/data/bestiary.json
Let it run. Your journal will fill up with monsters. It’s not too laggy but can take a long time because of how many monsters there are.
Bam. Done. If you are using the Shaped sheet, be sure to open up the NPC sheets and let them convert before using it.
You can convert stat blocks to JSON for importing via this converter.