The Joker & Batman in "Holiday Knights
Holiday Knights is the first episode of Season 1 of The New Batman Adventures. The main antagonists are Harley Quinn, Poison Ivy, Clayface, The Joker (The New Batman Adventures), & Mo, Lar, & Cur. It originally aired September 13th, 1997.
Plot:
Harley Quinn and Poison Ivy kidnap Bruce Wayne with Ivy's hypnotic lipstick, and use his credit cards to treat themselves to a Christmas shopping spree; Detective Harvey Bullock and Detective Renee Montoya stake out a Gotham department store for pick pockets, but in actuality, it turns out to be the return of Clayface; The Joker (The New Batman Adventures) plans to kill all the people celebrating in Gotham Square on New Years Eve with a sonic weapon. It's up to Batman and Robin (Tim Drake) to stop him before the stroke of midnight.
Cast:
Batman / Bruce Wayne - Kevin Conroy
Batgirl / Barbara Gordon - Tara Strong
Robin (Tim Drake) - Matthew Valencia
The Joker (The New Batman Adventures) - Mark Hamill
Clayface - Ron Perlman
Harley Quinn - Arleen Sorkin
Poison Ivy - Diane Pershing
Commissioner James Gordon - Bob Hastings
Veronica Vreeland - Marilu Henner
Detective Harvey Bullock - Robert Costanzo
Detective Renee Montoya - Liane Schirmer
Mary McSweeney - Rachel Davey
Little Boy - Tress MacNeille
Uniformed Cop - Corey Burton