The Big Monkeys were characters that appeared in the story segment of Party at Sea!.
They lived on an island where some islanders (Molly, Gil, Goby and Bubble Puppy) stumbled upon when their speed boat ran out of gas. As the islanders looked for parts to make a sailboat to get back home, they were scared by the Big Monkeys. When the islanders set sail, leaving the Big Monkeys, they felt bad for them and offered them a boat ride with them and they all lived happily ever after.
All three Big Monkeys look similar; gray fur, large heads and skirts made of leaves.