Vidmaster Challenge: Deja Vu

Vidmaster Challenge: Déjà Vu is an achievement in Halo 3: ODST and one of the Vidmaster Challenges. It is unlocked when you complete Coastal Highway on 4-player Legendary Live co-op, with Iron skull activated, and not using the Warthog or Scorpion at all. It is worth 25 Gamerpoints.

Trivia

 * The achievement is named due to its similarity to the previous Vidmaster Challenge achievement Annual, which also requires the Iron Skull and 4 player Legendary live co-op play.
 * At the beginning of the Highway there is a tunnel that leads underground there you will find 4 rocket launchers with 998 ammo and 2 mongooses. These only appear by putting the Iron skull on and on Legendary
 * Another similarity to the Vidmaster: Annual achievement is that all players may not use a Warthog or a Scorpion, leaving the only remaining option to be a Ghost or mongoose.