The Coal item in MM2 Roblox appears to have dropped during the Christmas 2021 event for the knife version, where it was obtainable through the Main Event tier 3. The Coal (2022) gun was obtainable during the Christmas 2022 event at Tier 2.

What that means

  • Coal Knife (2021): first dropped in the 2021 Christmas Event.
  • Coal Gun (2022): first obtainable in the 2022 Christmas Event.
  • Coal Effect: the wiki page says it is currently obtainable by crafting in the Christmas Event 2025.

Quick note

MM2 players sometimes say “coal set” to mean the knife, gun, or effect together, so the exact drop date depends on which Coal item you mean.

If you want the exact date for a specific Coal item, I can narrow it down to the knife, gun, or effect.