Kaguya at the fruit from the Shinju, God Tree. The fruit was overflowing with power. She gained the power of Chakra. The tree itself has been there for as long as humanity can remember. No other details about it's creation or origins beyond the fact it's the 10 Tailed Beast.
No one else dared to eat the fruit from the fear instilled into them by their own worship of the tree. The first person to eat fruit from the tree was granted phenomenal power, but the 10 tails did go on a rampage, hence why The Sage had to step in and seal it inside himself. Eating the fruit was considered a sin and so it was forbidden, probably why Kaguya was the first to actually attempt to eat it. As to why no one else tried, they probably believed the tales about the tree bringing it's wrath down on any who tried to steal the fruit.
Hope this answers your questions.