What is the Brain Tree?
The Brain Tree is a smart tree which exists in the Haunted Woods. This Brain Tree hungers for knowledge and will give you quests which when completed, will reward you handsomely.
What does it ask for?
The Brain Tree will ask for the time and place of a person. The only way in which you can find out is to do the Esohphagor Quest twice. Once for the time and once for the place. The Esophagor can also be found in the Haunted Woods next to the Brain Tree.
I saw on another site a list of Brain Tree answers.
No matter how much you try, they will never be right. Brain Tree answers are all randomized, and the only way to unlock the actual correct answers is by doing the Esophagor Quest twice.