If you are interested in exploring the subject, Boss GimGam Gltzdakka over on YouTube did a whole analysis video on whether Santa qualifies as PROPA ORKY

https://www.youtube.com/watch?v=fLyEPCft4MY

oh look slaanesh is giving people eggplants.

@Michael MaCleod: It's Corpse Starch, the Imperium's version of Soylent Green, but this setting is grimdark so its no secret that dead people are cycled into food. You can fully trust that the Imperium does not waste any part of human body after death.

What is in the can in the first panel? Corp Sta?

Merry Christmas! Thanks for another year of great work Jo

Guard - A primarch died to keep you all alive.
Blue berries - My brother died and would have wanted you happy regardless.
Chaos - I refuse to be outdone in gift giving.
Orks - Wagh! We still remember Santa! That red ummie gave a good fight and gave gifts! So have some Dakka!

Io Saturnalia, and may the Sol Invictus cover you in blessings.

Or, as another webcomic artist I follow put it: happy holydays to everyone, merry xmas to whoever wants it, and may your foes tremble before you!

Merry Christmas to you Jo, and your entire fan base.

Wouldn't the Imperium suppress knowledge of Santa so it wouldn't create a Warp entity based on him?