Land of the Giants (1968)

S1E18 Night of Thrombeldinbar

Fitzhugh disguises himself as an elf to bring joy to two orphaned kids. However, the festive atmosphere takes a dark turn when they disclose that their tradition involves sacrificing the elf to fulfill a wish. As the reality dawns on Fitzhugh, he must navigate the perilous situation while trying to protect himself and the children from the grim fate that awaits.