Although technically harmless, discovering a Boggart could cause an unsuspecting witch or wizard terrible psychological damage. The creatures took on the form of their victim's greatest fear and the only way to defeat them was through laughter - specifically via the use of the Boggart-Banishing Charm, and the incantation Riddikulus. Upon casting this spell, the Boggart would take on a more comical form, inspiring laughter and its eventual banishment. Remus Lupin taught this eventful spell to his Defence Against the Dark Arts class, to many amusing results!