Yasha is a hair youkai who's been a recurring character across multiple anime adaptations of the franchise.
He first showed up in the second episode of the original 1968 series, and has made scattered appearances ever since—popping up in episode ten of Devil's Melody: Yasha (1985), episode three of Guitar of Horror! Yasha (1996), and episode three of The Mysterious Melody! Yasha (2007). He also appeared in the Hakaba Kitarou anime in an episode called "Yasha vs. Dracula IV," and much later turned up in episode 87 of the 2018 adaptation Bloody Christmas.
Content compiled by AnimeList.moe from publicly available sources.