Make an event that has individuals fighting matches to randomly unlock reindeer for Santa to have to take presents around the world. 8 reindeer unlocks the big rewards while collecting individual reindeer unlocks a smaller reward. Can be a continuous event that doesn't end. Think morphling but instead of collecting helpers to fight a match were collecting reindeer for Santa to fly around the world
pretty cool idea but if I could suggest, each reindeer allows Santa to deliver X amount of presents to you and that amount increases with each reindeer. and each reindeer is harder to get. fighting grinches and his cohorts would be a cool way to get reindeer.
Top of my head event. All ideas are welcome to improve upon it 😃