This uncommon knife came from the 18th tier of the Main Event rewards during the Halloween Event 2021, so the only way to get one now is through trading. Its look fits the Halloween theme, which is why collectors of event items still ask about it. It sits in the same value range as Deathshard and Eternalcane. No chroma version exists.
Zombie (2021) is an Uncommon knife in Murder Mystery 2. Its combined value is 13, #15 of 202 uncommon items and #322 of 921 valued items overall. Demand is low: it sits in inventories for a while, and buyers often ask for a discount.
Closest in value: Deathshard (13), Elf (2015) (13), Eternalcane (13). Use them as a benchmark for a fair one-for-one trade.
Value history
What it is worth in other items
How many of each item equal one Zombie (2021) by value. Demand differs between items, so check it before you trade.