The Monkey Group must have been attacked because of the remarkable effects of the Monkey Wine that they made. Although it didn't attract the attention of the four giant beasts, it did bring the offspring of the Giant Poisonous Python. Even though the Monkey Group asked for help from members of the Giant Bear Family, they were still unable to fight off the python that had taken over their cave.
Upon this realization, Zhou Tian finally understood why that python was relentlessly chasing him.
Naturally, such enormous creatures like the four giant beasts are not easily grown. Besides needing supplies to meet their growth needs, the creatures themselves need to have corresponding talent. Otherwise, like the monkeys in the Monkey Group, having a lot of Monkey Wine doesn't necessarily result in formidable members within the tribe.