Some of the fondest memories I have while being lucky enough to be in charge of a Warner Brothers Studio Store Animation Art Gallery are getting to have some unique once-in-a-lifetime opportunities. One of which was attending a winter-time Gallery Collector’s Reception in New York City at the flagship nine-story WBSS store. Kevin Conroy (Batman) and Mark Hamill (Joker) were in town to sign cels and lithographs, and the place was packed. As the reception neared it’s end, those of us that had been there since well before the start continued our incessant nagging of Mark to do something special in person as The Joker. Well, he got up on the gallery managers desk and proceeded to sing "Jingle Bells, Batman Smells" as The Joker…and as you would expect it brought the house down. That’s something I’ll never forget.
One of the longest-selling pieces of the WSBB gallery was the "Batman Joker Storyboard," which was a large (3 foot by 3 foot) piece that depicted the storyboard of a sequence from "The Laughing Fish" episode of Batman : The Animated Series, fronted by a raised cutout of Batman & Joker back-to-back. Released for $275 in a limited edition of 2,500 pieces with 1,000 signed by Mark Hamill.
In celebration of this release, Acme Times (the newsletter of the Warner Brothers Stores) released a short article about Mark & his role as The Joker. This is from the June 1994 issue, and scanned for your enjoyment. 
Peace,
Chip
Best Joker ever.
Wow – I can’t imagine how cool that would have been to see & hear Mark Hamill sing that. And I remember the piece you have shown there. My brother was a lucky owner of one of the unsigned copies, but he sold it several years ago. Thanks for sharing Chip!
From the “It’s A Small World” department- I was AT that signing at the NYC store!
I was living in NYC rehearsing for a play. One of my fellow actors in the play had done Amadeaus with Mark and was friends with him so he tagged along. When Mark saw Arnie he recognized him right away and we got to go up and talk to him for a while. I got one of the postcards that was advertizing that piece signed by Mark. (I winder where I put that thing?)
Crazy stuff!