Harley Quinn: The Animated Series Volume 2: Legion of Bats!

"When last we checked in with Harley Quinn, she ate, she banged, and she killed--but now it's time for something a little different. Harley has found herself a part of a highly unlikely team--the Bat-Family. Meanwhile, Poison Ivy has found herself prepping for her new job--leader of the Legion of Doom. But while Harley and Ivy adjust to their respective new roles, a ghost from Ivy's past enters the fray and threatens the relationship between everyone's favorite clown/plant couple"--