You first see the Tree when you have come through The Oasis and you know it has to be The Tree but it looks like a fairly normal tree and you can't see any of the animals on it.   Once you spot it, it seems like a long walk to get to it.   As you realize you can't take your eyes off it, you notice that no one else can, either.

Click on the photo at right for a close up view of the trunk.