Cervulus The celebration is believed to have absorbed pagan overtones from Rome, Byzantine, and also some aspects of the local horned-deer god Cervulus/Kernunos, the latter mostly by association. Coronation of a donkey had long been part of the otherwise formal ceremonial feast of the hearth goddess Vesta. Roman mythology holds that by braying a warning, an ass saved Vesta from violence. http://www.helium.com/items/381539-what-is-the-feast-of-the-ass