Jack Frost is bad, even by “movie about a killer snowman” standards. And those are low standards.
The plot concerns—well, I’ve already mentioned the killer snowman, yes? Then, for most readers, I have described the plot in sufficient detail. For those still curious, the film opens with Federal agents transporting a serial killer (named Jack Frost, of course) to his execution. The icy conditions cause the paddy wagon to collide with a top-secret government tanker truck. The truck’s contents spray out, melting the killer's skin and bones. His liquid remains merge with the snow, granting him a second life as a snowman.
It's a reasonable setup. The problem lies in the execution. Had the film played as a straight horror whose antagonist happens to be a snowman, it might have worked. Just imagine the absurdist humor in swapping Michael Myers for a snowman in Halloween (1978). But Jack Frost drowns in a sea of camera winks and awkward comedy bits. It’s not a horror film, it’s a manufactured attempt at “so-bad-it’s-good” schlock.
For that approach to work, the titular killer snowman needs to be an anti-hero; someone we can perversely root for as he offs the self-centered jerk taking up two parking spaces during the holiday rush, the obnoxious boss who overworks his employees on Christmas Eve, and yes, even the ungrateful kid who’s unhappy with his gifts.
Jack Frost offers no such vicarious thrills. The serial killer turned snowman is out to fulfill a petty revenge pact against the small-town sheriff who arrested him. It’s an uninspired plot for an uninspired film that’s neither scary nor funny; and thus, not worth your time.