Leaf of faith, which is something that is not proved yet.
In the book, Pi is in a very very dangerous place, weird creatures, so he was scared and wanted to leave this island as soon as possible
The coolest and most interesting is that when Pi climb up a tree, found a round object that looks tasty, so when Pi eats it, he saw a complete set of teeth of a human’s, he suddenly found out that this land was a CARNIVOROUS LAND!!!
He’s really wanted to leave this island as soon as possible, but there was no way, so he think for a while, and figure out that he won’t be eaten.