The Proboscis monkey can be found along rivers and in swampy mangrove forests of Borneo, and can be found on all three nations that divide the island: Brunei, Indonesia, and Malaysia.

Among the largest of Asia’s monkeys, male proboscis monkeys can reach 50 pounds, although females attain only about half that size.

Proboscis monkeys survive mainly on a diet of leaves, seeds, and unripe fruits but will occasionally consume insects as well

Learn more here:
Singapore Zoo Proboscis Monkey page