After a scaring spree at a drive-in theater,
the Ghostly Trio's are confronted by Casper who is then confronted by Officer Snivel who informs him that his scare quota is down. The Trio take Snivel's whistle and blow it which summons Kibosh, the perfidious King of Ghosts. Kibosh explains Casper must
intentionally scare one person a year; the cowardice from humans just seeing Casper doesn't count. He threatens to send them to a void called The Dark if Casper fails to scare someone by December 25. To make sure Casper scares someone, he confiscates the Trio's haunting licenses and flings them to the Christmas-influenced town Kriss, Massachusetts, on account of the Trio's hatred of the holiday, where they meet the Jollimore Family. When Casper's good behavior starts to act up, which includes befriending the daughter of the family, Holly, the Ghostly Trio call in Casper's lookalike cousin
Spooky, who brings along his girlfriend Poil, to do the job disguised as Casper in the hope of fooling Kibosh. With Casper and Spooky unlikely to scare someone after a series of failed attempts the Trio decide to plot a scaring spree stealing every Christmas present in Kriss, in a reference to
How the Grinch Stole Christmas!, and taking them to the Jollimores' house where they plan to lure the townspeople then set off scary booby traps to go out with a bang before being banished to the Dark. Casper along with Spooky and Poil scare the Trio using a fake Kibosh made from the Jollimores' giant Santa. Casper then summons the real Kibosh using Snivel's whistle to inform him he scared the Trio, fulfilling his ghostly obligation, but Snivel informs Kibosh of the booby traps, violating the no scaring order on the Trio. To prevent Kibosh from banishing them to the Dark, the Trio claim the traps are a Christmas gift for Kibosh; since he enjoys watching torture, the trio spring them. After the act, Kibosh accepts the Trio's claim and returns their haunting licenses before leaving with Snivel. The film ends with the remaining ghosts celebrating Christmas with the Jollimore family. ==Cast==