I just discovered over at popvinyl.net that Funko has released an Arkham Asylum nurse costume Harley Quinn! The figure is currently a Hot Topic 'pre-release' exclusive, which means for a limited time you can only find her at Hot topic, and later you will find her at other POP vinyl retailers.
Hot Topic exclusive POP vinyl Harley Quinn with mallet.
Also available is Batman, Poison Ivy, Killer Croc and The Joker in POP vinyl Arkham Asylum form.
pic credit @Funko_mania