Mangrees are very intelligent, social, inquisitive, omnivorous, monkey-like creatures near the center of Haven's food chain. Their primary predator appears to be the Camoudile, but the Mangrees have built wooden nests in the treetops to avoid them. Although he hunted the Mangrees in the North Jungle to near-extinction, Achenar later showed extensive interest in Mangrees and even created a sound device to issue limited orders to the Mangrees, whom he eventually came to consider his friends - they even gave him a name.
Because of Achenar's extensive hunting, the Mangrees in the North Jungle will run away from any human. However, the Mangrees in the South Jungle have never been given cause to fear people, and will intently watch anyone who wanders through their territory.