Kasibarenini is singled out in Matsigenka demonology as the foremost and most dangerous of the kamagarini, the brood of little devils fathered by the counter-creator Kientibakori. Where the kamagarini as a class beset the forest with sickness and misfortune, Kasibarenini is the named and personified worst of them, a demon who takes on human likeness to approach the ailing and the solitary and draw them toward death. He belongs to the world of the tobacco shaman's adversaries, one of the specific malevolent beings the seripigari must recognise and repel in the defence of the sick.