In Cartman's Christmas Story, the Anti Christ is the Woodland Critters' savior, much like the way Jesus Christ is the savior for the Christians. The anti-christ comes into the world after Porcupiney gets pregnant after having sex with Satan.
The critters get Stan to kill the mountain lion and build them a manger for the birth using cuteness to lure Stan into their trap.
Kyle is chosen to be the host for the anti-christ, since he's Jewish and has never been baptized. The anti-christ enters inside him, but it's not long before Kyle wants him out.
Using their abortion techniques learned in the Abortion clinic, the mountain lion cubs are able to safely remove the little demon out of Kyle's ass, which Santa proceeds to smash with a hammer.