Arkham Asylum's patients include Harley Quinn.
Arkham 's high-profile patients are often from Batman 's rogues gallery , such as the Joker , Two-Face , Poison Ivy , the Riddler , Harley Quinn , Clayface , Mad Hatter , Killer Croc , Mr. Freeze , and Scarecrow .	Batman	Batman	rogues gallery	List of Batman Family enemies#Classic Rogues Gallery	the Joker	Joker (character)	Two-Face	Two-Face	Poison Ivy	Poison Ivy (comics)	the Riddler	Riddler	Harley Quinn	Harley Quinn	Clayface	Clayface	Mad Hatter	Mad Hatter (comics)	Killer Croc	Killer Croc	Mr. Freeze	Mr. Freeze	Scarecrow	Scarecrow (DC Comics)
