The RAAM's Shadow Add-on for Gears of War 3 has 9 achievements worth 175 gamerscore.
Complete "RAAM's Shadow" in Arcade Campaign on any difficulty.
As RAAM, kill 50 Gears using your Kryll.
Complete "RAAM's Shadow" in Standard Campaign on any difficulty.
Complete "RAAM's Shadow" in 4 player co-op in either Arcade or Standard mode.
As Mauler, kill 10 Gears by reflecting their bullets using your shield.
Using the Hammer of Dawn Command Center, kill 50 Locust.
Using the Loader, kill 10 Locust.
Play 10 matches of Versus as a member of Zeta (Barrick, Tai, Minh, or Valera)(Standard or Casual).
As RAAM, execute Minh 10 times in Versus MP (Standard or Casual).