The Mothman
Art by Kim Holm on https://denungeherrholm.smugmug.com/,
used under Creative Commons Attribution 4.0 International License.
The mothman, a cryptid that has gripped imaginations since 1966. Here it is imagined as both a fey creature and a vampire, and can provide an interesting challenge to your adventurers.
sheet here https://www.patreon.com/posts/109860680