Noone knows for sure how the Green Monkey Weasels came to be, but many have their theories.
The ancient Mayans believed that the Weasels were punk rock Gods placed upon the Earth to bring them messages of anarchy, beastiality, and masturbation.
Nowadays, people don't give a shit were they came from.The Romans believed that the Weasels were professors of wisdom. They believed that the Weasels were sent to them from the gods above to help them to develop a government more suited to the needs of the people.
The Sung-Yung Chow Dynasty of China worshipped the Weasels as sages, believing them to possess powers not of this world. Super-human skank powers.
The Eskimo's believed that the Weasels were sent from the sea, to teach them proper whaling technique. Alas, the eskimo's were wrong.
My dad believes that the Weasels were created to annoy the entire neighborhood.
The Native Americans believed that the Weasels were products of their excessive use of hallucinogenic drugs, and were punishment for improper use of peoti.
In Ancient Greek the Weasels were believed to have spawned from the anus of Zues. They were worshipped as the God of Feces until the Greeks figured that worshipping Ass Gods was fucked up.
The Biblical Sodomists didn't pay attention to the Weasels, because they were too busy with dicks up their asses.