Vicus

Viscus is a demon who preys on witch children, who are good, in an attempt to corrupt them into evil. He cloaks himself so that only the children can see him and gains their trust. Once he gains he asks for a personal item, to show the trust, then curses it turning the child evil once they touch it again.

Viscus attempted to corrupt Wyatt when he was two and a half, causing Leo and the sisters to believe that he had an imaginary friend. He eventually gained Wyatt's trust and cursed his teddy bear, turning him evil. Leo reversed this magic by getting Wyatt to trust him and give him the teddy bear.