|“||Holy Mackerel is a fighting-utility weapon from NRF's research lab. It is classified as biological hazards that pose a threat the the health of living organisms, primarily that of humans.||”|
|— Weapon Description|
This melee weapon that appeared and was obtainable during a Valve weekend promotion on February 16, 2012 where in Alliance of Valiant Arms, players earn the Holy Mackerel and where Team Fortress 2 players earn the Black Rose knife once you achieve the "1st One Down" achievement.
- The Holy Mackerel is the melee weapon from Scout class in Team Fortress 2.
- Came from event where Team Fortress 2 gets Black Rose and Alliance of Valiant Arms gets the melee weapon Holy Mackerel.
- This was awarded to the players that completed the achievement 1st One Down.
- As the cross-promotion, the Black Rose is the in-game award for Team Fortress 2 players.
- "Holy Mackerel" as phrase is form of a minced oath.