A google search gone wrong: Allison meant to look up the dream symbolism of a beautiful black and white horse, but instead, it sent her on a nosedive into creepy pictures of mythological horse creatures — which brings you this bonus episode! We present to you: the Nuckelavee, the most nightmarish horse demon of Orcadian Mythology, and La Sihuanaba, the alluring dame of Mexican and Central American mythologies. Enjoy Friends!
Sources:
https://en.wikipedia.org/wiki/Nuckelavee
https://lanternhollow.wordpress.com/2012/04/06/briggs-beasties-nuckelavee/
https://www.youtube.com/watch?v=LYIuAXxGxcg
https://en.wikipedia.org/wiki/Sihuanaba
https://www.youtube.com/watch?v=OhH8KDg6zhU&t=152s (I used this video for my pronunciations, which I still butchered. -M.)
Not a source but I found this to be an interesting take on the story of La Siguanaba:
