Freeza Day

In the world of Dragon Ball Z Abridged, Santa never made it to Planet Vegeta, mostly because they kept trying to shoot his sleigh down, so instead of Christmas we have Freeza Day. While this was mostly just a small running gag, Freeza Day became an actual celebrated holiday in Hell for the natives of HFIL, with each house giving the Space Emperor a present, after which he'll blow up the home of the one with the worst gift.

Example of:
You Mean "Xmas"