Art and drawing references
Always visit the galleries and read the terms of use before using images.
Stock Images
AdorkaStock
https://www.deviantart.com/senshistock/gallery
Waoh... so that's what "humans" look like!
faestock
https://www.deviantart.com/faestock
More body poses!
unsplash
https://unsplash.com/
Many general stock image websites have stolen content. This one doesn't!
Art references
posemaniacs
https://www.posemaniacs.com/
Hundreds of human poses for drawing practice, both 3D and real life images.
x6ud
https://x6ud.github.io
Skull... rotate... :D