Reality-warping main antagonists from series known for tricking people, who at first didn't seem to have much of a role in their series, but were later revealed to be the ultimate evil (Flowey at first seemed like a random a-hole you first encounter and Bill just seemed to be a one-off villain from Season 1). Both also watched the main, underage character(s) from behind the scenes and occasionally pop-up to toy with them, eventually leading to the point where they tricked the hyperactive sibling of one of their series most popular character (Mabel and Papyrus) into leading them to succeed in their plans (Flowey tricked Papyrus to reunite everyone during Asgore's fight in the Pacifist Run, and Bill tricked Mabel into giving him the rift while possessing Blendin).