They use their tails for grasping. Their tails can hold onto a branch like another hand. Old World monkeys have thin noses with small nostrils. Their tails are tiny and straight. All monkeys have two arms, two legs, five fingers, and five toes.
Monkeys vary in shape, size, and colors.
Monkeys vary in size. The smallest is the pygmy marmoset. It is only about 6 inches long. The mandrill is one of the largerst monkeys. It may grown as long as 32 inches.