Maasq has done a great job of creating an engineer that helps building non-player characters for use in Fantasy Grounds. His software cut down the amount of days needed for this project by a pretty good chunk, and for that I'm extremely grateful. It also generates the wonderful sorted lists by terrain and mythological origin found in the library section. Thank you Maasq for the great effort.
So first a few disclaimers. This website believes, or at least claims to believe, that it is "Looking beyond the visible world." That means that what inspiration I've taken from them for fantasy, they may believe to be real. This website also has advertisements that are NOT family friendly, proceed at your own risk.
That being said, they did have a list of fey creatures with basic descriptions that sparked some inspiration.
Inuit Mythology.net is a great source of arctic creatures which inspired several new additions.
Norse Mythology.net is a great website that has lots of information about different creatures in mythology and some of the stories behind them. Most of this information is about individual beasts, monsters, elves, dwarfs, etc. so I took the liberty of generalizing them. Instead of it being a beast you can only encounter one of, it is a group of beasts that resemble that legendary beast.