Cheerilee is the main antagonist of the infamous "grim-dark" story known as Cheerilee's Garden - which is considered one of the most graphic and well-known of the innumerable horror-based stories to come from the MLP franchise: the exact reasons behind why this show has gained such a large number of adult-themed fan-fiction is not really known but Cheerilee's Garden shows that even background characters are not immune to this phenomena. Cheerilee is introduced in this story as emotionally unstable, seeing her students as being parasitic in nature - to the point she envisions the world as a garden and the children as weeds which are strangling the "good": her insanity builds up until one day she snaps completely and decides she must kill all of her students in order to "purify" the world.
Not wishing to arise suspicion from parents or other members of Ponyvile Cheerilee arranges a play for the children, using the event to lure her victims into one place whilst also providing a distraction as she uses trapdoors to deliver each child to an elaborate death-trap where she tortures and kills them.
In the end Cheerilee succeeds in killing all of the children and fakes a massive fire so that Ponyvile believes the whole incident to be a terrible accident - thus Cheerilee (like many other killers in these stories) evades any punishment.
type of villain-Spree-Killers,Villains With Mental Illness,Sadists