A video shared on social media shows the dog- monkey duo seem inseparable. They rushed at each other, playing in opposite directions before the monkey climbed up their backs, sticking tightly to the dog's backs.
According to the police of Cartagena city, Colombia, the monkey was caught from its natural habitat just a few weeks after being born. At that time, local people brought a dog that had just lost their 5 cows, with the purpose of taking care of the monkey.
Now, they become extremely attached. The monkey is aggressive towards anyone who wants to approach the dog. It even spends almost the whole day on the dog's back. The people in charge of nature and environment want to separate the two animals to bring the monkeys back into the wild, but many others recommend keeping them together.
This is a "hat monkey" species, currently priced at 1,200 USD on the black market.