In addition to being a slight rewriting of the classic Jingle Bells line, the part that says "sing a slaying song tonight" is modeled on the fact that "sleigh" and "slay" sound phonetically identical to each other, and the effect involves you 'slaying' some creatures (or at least attempting to)
List of ALL MILL CARDS from MTG If you like my deck, please cite the source and upvote
Bloomburrow by Justin Gerard, created as a promotional poster for Magic: The Gathering Bloomburrow, showcases a vibrant menagerie of woodland creatures encircling a proud mousefolk hero presenting a glowing fang
Additionally, widening the scope of the choices to nonland permanent card seems more fitting, or perhaps artifact, enchantment, instant, or sorcery if you'd rather go for non-character cards
Use the cantrips to set up your early turns (and occasionally plan out a timely Miracle Temporal Mastery), Spreading Seas to slow them down, hopefully flash in Dictate of Kruphix on their end step, untap and hold up Cryptic Command or Gigadrowse, and then cast Time Warp on Turn 5 and never pass the turn back to them
