Find the Poster of the Missing Man
Halo 3 MILK CARTON – Achievement / Trophy Guide
This tiny hippo toy can be found on the map “Foundry”. Create a custom game and choose any game mode. Look for the yellow forklift and the big “A” and “B” signs. The hippo can be found in between this on a little pile of dirt. Zoom in on it and the achievement should pop after a few seconds.