This one's from 1997's DC Universe Holiday Bash, back when there were still New Gods:
Now I know that I've already declared the title of Best Santa Ever, but I think that Highfather definitely comes in at a strong number two. Also, "moth-eaten hippie Abe Lincoln."
The story: a mall manager or owner or something sees Highfather and Orion wandering around and thinks that they're his Santa crew, based on ambient beard-magnificence, I guess. Highfather being, like, eight feet tall doesn't seem to be a problem for the guy until the costume doesn't fit.
Don't worry, though - Christmas isn't ruined. Tallpop uses his amazing power to make everything portentous and:
... ends up looking pretty cool! Not to be outdone, Orion puts his mind/Mother Box to things and becomes...
Actually, he becomes a pretty terrifying elf.
The rest of the story plays out kind of like that scene in Hogfather (by Terry Pratchett, natch) where Death is doing the mall Santa thing, though just the heartwarming stuff - no pig urine jokes. Check this out:
Dude, Highsanta is huge.
Such a great Christmas story. Right up there with the Justice League where Plastic Man claims that Santa has heat vision (that one's for next year, I'm afraid).
"FIVE LEGION RINGS!"