This deer with a genetic defect causing it to grow a single, centrally placed horn is alive and well and living in Italy.

Thanks again to Christian for a great link: The Obakemono Project, “A Gaijin’s Guide to the Fantastic Folk Monsters of Japan”, with descriptions and illustrations - from the well-known oni and kappa to the abumi-kuchi, a furry creature formed from a stirrup, and the sagari, a ghostly apparation of a horse’s head hanging from a nettle tree.