The Crimson Map Pack Add-on for Halo 4 has 8 achievements worth 250 gamerscore.
In Crimson DLC matchmaking, get a kill while airborne in a Warthog.
In Crimson DLC matchmaking, kill 20 enemies with a detached Machine Gun Turret.
In Crimson DLC matchmaking, kill a player while airborne from a Man Cannon.
In Crimson DLC matchmaking, kill 20 enemies using the Mantis' stomp attack.
In Crimson DLC matchmaking, board an enemy Mantis.
In Crimson DLC matchmaking, score the killing blow on a Mantis.
In Crimson DLC matchmaking, shoot an enemy who’s airborne from a Man Cannon.
In Crimson DLC matchmaking, kill an enemy with melee when landing from a Man Cannon.