Sanni Yakku
Sanni Yakku are the 18 disease demons of Sinhala Sri Lankan demonology — each causing a specific illness (fever, madness, skin conditions). Invoked in thovil exorcism rituals where masked dancers (ves) embody them. Documented by Obeyesekere, Wirz, Kandyan medical texts. Not a single demon but a cohort; king is Maha Sohona. Central to Sri Lankan traditional healing (demonology as medicine).