Richard Parker symbolizes all the lessons (no matter how difficult) his father taught him.  Without his fathers lessons, Richard Parker would not have existed and Pi most certainly would have died.  So in the movie the author claims that Pi was the tiger, but only from his fathers love and lessons in life.  A beautiful movie and a test to ones faith in God and the overcoming of terrible odds.  The sad truth is that the story without the animals was most likely the true story.  Pi crying at the end when the people dragged him off was the saddest part of the movie for me, as it was then that it all set in and was grieving cause he was unable to show much he loved his father and unable to say goodbye to him.  my father died of a heart attack last year.  he was my best friend.  and i grieve everyday that he is gone and i regret never thanking him for being such a great father.  The movie has moved me like no other movie ever has and the acting was some of the best i have ever seen.  highly recommend it to everyone!