Mystery Inc. was investigating a ghost haunting a department store at Christmas time going by the terms of Charles Dickens' The Christmas Carol - Ghost of Christmas Past, Present, and Future. Just then, Harley Quinn appeared, claiming she was turning from crime to ghost hunting, and wanting to join the gang. They didn't want to accept her application (they had recently turned down Doctor Thirteen), but they reluctantly accepted.
Harley began searching for clues, but Velma turned towards suspects and motives. Daphne proposed Assistant Manager Humphrey Middleman, Fred thought it was Salespeople Doug Chippendale and Sarah Shaker, and Velma thought of the rival store: Bargain Benny. Harley threatened the store workers, causing panic, before Daphne calmed her down. Then they started looking for clues, but the ghost then attacked. Before long, Harley started chasing the ghost with her mallet, and cornering it. However, before Fred could unmask it, the Joker broke in looking for Harley.
Joker came because Harley had stolen her Christmas Present before running off, and he wanted it back. Sad that he had not come for her, Harley attacked the Joker, before runnig away with the rest. Joker summoned Harley's hyenas, named Scooby and Scrappy to appease her. Taking advantage of the carnage, Shaggy and Scooby tried to flee, but were stopped by some goons. Meanwhile, Harley opened her present, revealing a detonator for Joker Gas bombs spread across Gotham City. Harley, loving the present, went back to her lover, just in time for Scooby to hit Joker and send the detonator flying. Batman appeared and caught it and tied up the Joker. The goons were beaten by Robin, and Batgirl knocked out Harley. They were all retrained and loaded onto a van going towards Arkham Asylum. Before leaving, Harley reveled that Chippendale was the ghost, because he had the same shoes as it.
- Ghost of Christmas Past (only appearance)(photograph)(Doug Chippendale's disguise)
- Ghost of Christmas Present (only appearance)(photograph)(Doug Chippendale's disguise)
- Doug Chippendale (only appearance)(no lines)
- Christmas Spirit (only time mentioned)
- Chaunted Chanukah (only time mentioned)
- Ghost of Christmas Yet to Come (only appearance)(Doug Chippendale's disguise)
- Scooby (hyena) (only appearance)(no lines)
- Scrappy (hyena) (only appearance)(no lines)
- Punch or Judy (only appearance)(no lines)(unnamed)
- Gaggy (only appearance)(no lines)(unnamed)
- Sarah Shaker (only appearance)(no lines)
- Baby products salesperson (only appearance)
- Poison Ivy (mentioned)
- Doctor Thirteen (mentioned)
- Phantom Stranger (mentioned)
- Bargain Benny (photograph)
- Internal Revenue Service (mentioned)
- Miscellaneous Gotham City citizens (only appearance)(no lines)(thought bubble)
- Arkham Asylum van driver 1 (only appearance)
- Arkham Asylum van driver 2 (only appearance)(no lines)
- Gotham City
- Harley Quinn's giant mallet
- Harley Quinn's giant magnifying glass
- Joker Gas (thought bubble)
- Joker's detonator
- Batmobile (mentioned)
- Arkham Asylum van
|Humphrey Middleman||To take over the manager's job.|
|Sarah Shaker||Turned down for a raise.|
|Doug Chippendale||Turned down for a raise.|
|Bargain Benny||Store competitor.|
|Doug Chippendale as the Ghost of Christmas Past, Ghost of Christmas Present, and Ghost of Christmas Yet to Come||Revenge for not getting a raise.|
The following credits try to match how they are displayed in the comic as much as possible:
- Writer~ Sholly Fisch
- Artist~ Dario Brizuela
- Colorist~ Silvana Brys
- Letterer~ Saida Temofonte
- Cover artist~ Brizuela with Franco Riesco
- Editor~ Kristy Quinn
- Special thanks to~ Brittany Holzherr
- Harley Quinn created by Paul Dini and Bruce Timm
- This is the first Scooby-Doo! Team-Up Christmas special.
- Harley named her pet hyenas after Scooby and his nephew, Scrappy. In Batman: The Animated Series, Harley also had a couple of pet hyenas, named Bud and Lou, after Bud Abbot and Lou Costello.
- The title is a play on "Happy holidays."
- Harley Quinn and the Joker are based on their designs from Batman: The Animated Series, while Batman and Robin are still based on their The New Scooby-Doo Movies/Super Friends designs. This is different from the Joker's cameo in Template:SDT2, where he was based on his Silver Age/Bronze Age design.
- Harley refers to the Ghost of Christmas Yet to Come as Casper, after Casper the Friendly Ghost.
- None known.
Inconsistencies/continuity errors and/or goofs/oddities
- The last time Harley appeared in Gotham Ghouls, she claimed the Joker was always talking about how he wanted vengeance against Mystery Inc., but when Fred points this out to him, he doesn't remember them.
- Harley makes the connection between one of the ghosts and Doug Chippendale having baby powder on their feet, but she wasn't there when the baby products salesperson spoke about that (unless she was just standing in the background).