This is unlocked by sneaking past a dinosaur whilst using Camoflauge.
This is a story related achievement that can't be missed.
The first instance of this in the story is during the level 'Eric Kirby' the fourth level of the 'Jurassic Park 3' film.
Half way through the level you will gain control of Eric, who has the camo ability. Activate it by holding
.
There is a part in the story where you must use your Camoflauge and sneak past a dinosaur to progress.