Tainted Organic Monster
First appeared in Touhou 19: Unfinished Dream of All Living Ghost as a boss and playable character.
Chiyari is a Tenkajin who is often confused for a chupacabra. She has wavy, purple hair with a single horn on her head. She wears a t-shirt with the words "Welcome to Hell" or "I ♥ LOVE (OLD) HELL" or "やっぱ旧だよね!" (It's gotta be Old (Hell)!) written on it, and carries test tubes and syringes on her shorts.
Chiyari is a shut-in who lives in the Former Hell of Blood Pools and is acquainted with characters like Kaenbyou Rin and Reiuji Utsuho. She works with the Gouyoku Alliance as part of their operations to take over the surface world. In reality, as with Son Biten and Mitsugashira Enoko, she is a spy whose true allegiance lies with Nippaku Zanmu. She was tasked with sabotaging the Gouyoku Alliance's invasion plans from within by playing them for time as part of Zanmu's gambit to prevent a surface war. Unlike with Saki or Yachie, Yuuma never trusted her, but still keeps Chiyari around as a future asset against Zanmu.