Comes from Saint Nikilis's challenge in the 2020 Christmas Event, and that event is long over, so the only way to get this legendary knife now is through trading. It's a holiday collectible for players who want something from that event in their inventory. Traders usually group it with items like Cowboy, Gingerbread (2019) and Hazard (2022).
Santa's Spirit is a Legendary knife in Murder Mystery 2. Its combined value is 4, #22 of 89 legendary items and #432 of 921 valued items overall. Demand is very low: it sits in inventories for a while, and buyers often ask for a discount.
Closest in value: Cowboy (4), Gingerbread (2019) (4), Hazard (2022) (4). Use them as a benchmark for a fair one-for-one trade.
Value history
What it is worth in other items
1×Cowboy
1×Gingerbread (2019)
1×Hazard (2022)
1×Nobledragon
1×Peppermint (2020)
1×Purple Pumpkin
1×Santa's Magic
1×Scratch (2016)How many of each item equal one Santa's Spirit by value. Demand differs between items, so check it before you trade.