Okay, this is going to sound stupid, but I remember an animated Christmas special (cel animation, not stop-motion) from around the late 70s/early 80s about three extraterrestrials who came to Earth on Christmas. I remember something about them being analogous to the Magi, looking for a child who was just born to give him gifts.
That sounds like Cosmic Christmas, a Canadian production.
And on googling that title, that’s exactly what it was! Thanks, JThunder!
Irrelevant trivia: Cosmic Christmas was the working title of the Rolling Stones’ 1967 album Their Satanic Majesties Request. (There’s even a weird electronic version of “We Wish You a Merry Christmas” on the finished album.)