Kibosh, supreme ruler of all ghosts, decrees that casper must scare at least one person before Christmas Day so Casper visits Kriss, Massachusetts where he meets the Jollimore family and sets out to complete his mission. As usual, kindhearted Casper has a ghastky time trying to scare anyone; so The Ghostly Trio, fed up with his goody-boo-shoes behavior, secretly hires Casper's look-alike cousin Spooky to do the job-with hilarious results.