The kids put a magic hat on a snowman and he comes to life and does battle with baby Jesus.

How Kenny Dies : Killed by Frosty

Stan, Kyle, Cartman, and Kenny are singing "We Wish You A Merry Christmas" when Stan remembers Kyle's Jewish. Kyle and Cartman get in a fight which ends when Jesus appears. He's come seeking retribution at the mall. The kids bring him there where he finds Santa Claus and begins to fight with him. During the fight, they accidentally kill Kenny. Both Santa and Jesus ask the boys for help and Kyle and Cartman end up fighting again...causing everyone else to fight. Stan wonders, "What would Brian Boitano do?"...and right on cue, he skates in and gives them some advice. The kids convince Santa and Jesus to stop fighting and become friends. As a result, the boys learn the true meaning of Christmas...presents.

How Kenny dies : Decapitated by Santa